| blob | 34d78741d411610d6ccb6514412737b98f8fddca |
1 /*
2 ** 2001 September 15
3 **
4 ** The author disclaims copyright to this source code. In place of
5 ** a legal notice, here is a blessing:
6 **
7 ** May you do good and not evil.
8 ** May you find forgiveness for yourself and forgive others.
9 ** May you share freely, never taking more than you give.
10 **
11 *************************************************************************
12 ** This file contains routines used for analyzing expressions and
13 ** for generating VDBE code that evaluates expressions in SQLite.
14 */
17 /* Forward declarations */
21 /*
22 ** Return the affinity character for a single column of a table.
23 */
27 }
29 /*
30 ** Return the 'affinity' of the expression pExpr if any.
31 **
32 ** If pExpr is a column, a reference to a column via an 'AS' alias,
33 ** or a sub-select with a column as the return value, then the
34 ** affinity of that column is returned. Otherwise, 0x00 is returned,
35 ** indicating no affinity for the expression.
36 **
37 ** i.e. the WHERE clause expressions in the following statements all
38 ** have an affinity:
39 **
40 ** CREATE TABLE t1(a);
41 ** SELECT * FROM t1 WHERE a;
42 ** SELECT a AS b FROM t1 WHERE b;
43 ** SELECT * FROM t1 WHERE (select a from t1);
44 */
53 }
60 }
61 #ifndef SQLITE_OMIT_CAST
65 }
66 #endif
74 );
75 }
79 }
87 }
89 }
91 }
93 /*
94 ** Make a guess at all the possible datatypes of the result that could
95 ** be returned by an expression. Return a bitmask indicating the answer:
96 **
97 ** 0x01 Numeric
98 ** 0x02 Text
99 ** 0x04 Blob
100 **
101 ** If the expression must return NULL, then 0x00 is returned.
102 */
111 }
115 }
118 }
121 }
124 }
129 }
140 }
149 }
152 }
154 }
157 }
161 }
163 /*
164 ** Set the collating sequence for expression pExpr to be the collating
165 ** sequence named by pToken. Return a pointer to a new Expr node that
166 ** implements the COLLATE operator.
167 **
168 ** If a memory allocation error occurs, that fact is recorded in pParse->db
169 ** and the pExpr parameter is returned unchanged.
170 */
176 ){
183 }
184 }
186 }
191 ){
192 Token s;
196 }
198 /*
199 ** Skip over any TK_COLLATE operators.
200 */
205 }
207 }
209 /*
210 ** Skip over any TK_COLLATE operators and/or any unlikely()
211 ** or likelihood() or likely() functions at the root of an
212 ** expression.
213 */
224 }
225 }
227 }
229 /*
230 ** Return the collation sequence for the expression pExpr. If
231 ** there is no defined collating sequence, return NULL.
232 **
233 ** See also: sqlite3ExprNNCollSeq()
234 **
235 ** The sqlite3ExprNNCollSeq() works the same exact that it returns the
236 ** default collation if pExpr has no defined collation.
237 **
238 ** The collating sequence might be determined by a COLLATE operator
239 ** or by the presence of a column with a defined collating sequence.
240 ** COLLATE operators take first precedence. Left operands take
241 ** precedence over right operands.
242 */
252 ){
259 }
261 }
265 }
270 }
275 }
281 /* The Expr.x union is never used at the same time as Expr.pRight */
289 }
290 }
291 }
293 }
296 }
297 }
300 }
302 }
304 /*
305 ** Return the collation sequence for the expression pExpr. If
306 ** there is no defined collating sequence, return a pointer to the
307 ** default collation sequence.
308 **
309 ** See also: sqlite3ExprCollSeq()
310 **
311 ** The sqlite3ExprCollSeq() routine works the same except that it
312 ** returns NULL if there is no defined collation.
313 */
319 }
321 /*
322 ** Return TRUE if the two expressions have equivalent collating sequences.
323 */
328 }
330 /*
331 ** pExpr is an operand of a comparison operator. aff2 is the
332 ** type affinity of the other operand. This routine returns the
333 ** type affinity that should be used for the comparison operator.
334 */
338 /* Both sides of the comparison are columns. If one has numeric
339 ** affinity, use that. Otherwise use no affinity.
340 */
345 }
347 /* One side is a column, the other is not. Use the columns affinity. */
350 }
351 }
353 /*
354 ** pExpr is a comparison operator. Return the type affinity that should
355 ** be applied to both operands prior to doing the comparison.
356 */
370 }
372 }
374 /*
375 ** pExpr is a comparison expression, eg. '=', '<', IN(...) etc.
376 ** idx_affinity is the affinity of an indexed column. Return true
377 ** if the index with affinity idx_affinity may be used to implement
378 ** the comparison in pExpr.
379 */
384 }
387 }
389 }
391 /*
392 ** Return the P5 value that should be used for a binary comparison
393 ** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2.
394 */
399 ){
403 }
405 /*
406 ** Return a pointer to the collation sequence that should be used by
407 ** a binary comparison operator comparing pLeft and pRight.
408 **
409 ** If the left hand expression has a collating sequence type, then it is
410 ** used. Otherwise the collation sequence for the right hand expression
411 ** is used, or the default (BINARY) if neither expression has a collating
412 ** type.
413 **
414 ** Argument pRight (but not pLeft) may be a null pointer. In this case,
415 ** it is not considered.
416 */
421 ){
432 }
433 }
435 }
437 /* Expression p is a comparison operator. Return a collation sequence
438 ** appropriate for the comparison operator.
439 **
440 ** This is normally just a wrapper around sqlite3BinaryCompareCollSeq().
441 ** However, if the OP_Commuted flag is set, then the order of the operands
442 ** is reversed in the sqlite3BinaryCompareCollSeq() call so that the
443 ** correct collating sequence is found.
444 */
450 }
451 }
453 /*
454 ** Generate code for a comparison operator.
455 */
465 ){
475 }
481 }
483 /*
484 ** Return true if expression pExpr is a vector, or false otherwise.
485 **
486 ** A vector is defined as any expression that results in two or more
487 ** columns of result. Every TK_VECTOR node is an vector because the
488 ** parser will not generate a TK_VECTOR with fewer than two entries.
489 ** But a TK_SELECT might be either a vector or a scalar. It is only
490 ** considered a vector if it has two or more result columns.
491 */
494 }
496 /*
497 ** If the expression passed as the only argument is of type TK_VECTOR
498 ** return the number of expressions in the vector. Or, if the expression
499 ** is a sub-select, return the number of columns in the sub-select. For
500 ** any other type of expression, return 1.
501 */
513 }
514 }
516 /*
517 ** Return a pointer to a subexpression of pVector that is the i-th
518 ** column of the vector (numbered starting with 0). The caller must
519 ** ensure that i is within range.
520 **
521 ** If pVector is really a scalar (and "scalar" here includes subqueries
522 ** that return a single column!) then return pVector unmodified.
523 **
524 ** pVector retains ownership of the returned subexpression.
525 **
526 ** If the vector is a (SELECT ...) then the expression returned is
527 ** just the expression for the i-th term of the result set, and may
528 ** not be ready for evaluation because the table cursor has not yet
529 ** been positioned.
530 */
541 }
542 }
544 }
546 /*
547 ** Compute and return a new Expr object which when passed to
548 ** sqlite3ExprCode() will generate all necessary code to compute
549 ** the iField-th column of the vector expression pVector.
550 **
551 ** It is ok for pVector to be a scalar (as long as iField==0).
552 ** In that case, this routine works like sqlite3ExprDup().
553 **
554 ** The caller owns the returned Expr object and is responsible for
555 ** ensuring that the returned value eventually gets freed.
556 **
557 ** The caller retains ownership of pVector. If pVector is a TK_SELECT,
558 ** then the returned object will reference pVector and so pVector must remain
559 ** valid for the life of the returned object. If pVector is a TK_VECTOR
560 ** or a scalar expression, then it can be deleted as soon as this routine
561 ** returns.
562 **
563 ** A trick to cause a TK_SELECT pVector to be deleted together with
564 ** the returned Expr object is to attach the pVector to the pRight field
565 ** of the returned TK_SELECT_COLUMN Expr object.
566 */
572 ){
576 /* The TK_SELECT_COLUMN Expr node:
577 **
578 ** pLeft: pVector containing TK_SELECT. Not deleted.
579 ** pRight: not used. But recursively deleted.
580 ** iColumn: Index of a column in pVector
581 ** iTable: 0 or the number of columns on the LHS of an assignment
582 ** pLeft->iTable: First in an array of register holding result, or 0
583 ** if the result is not yet computed.
584 **
585 ** sqlite3ExprDelete() specifically skips the recursive delete of
586 ** pLeft on TK_SELECT_COLUMN nodes. But pRight is followed, so pVector
587 ** can be attached to pRight to cause this node to take ownership of
588 ** pVector. Typically there will be multiple TK_SELECT_COLUMN nodes
589 ** with the same pLeft pointer to the pVector, but only one of them
590 ** will own the pVector.
591 */
598 }
606 /* This must be a vector UPDATE inside a trigger */
609 }
610 }
612 }
614 }
616 /*
617 ** If expression pExpr is of type TK_SELECT, generate code to evaluate
618 ** it. Return the register in which the result is stored (or, if the
619 ** sub-select returns more than one column, the first in an array
620 ** of registers in which the result is stored).
621 **
622 ** If pExpr is not a TK_SELECT expression, return 0.
623 */
626 #ifndef SQLITE_OMIT_SUBQUERY
629 }
630 #endif
632 }
634 /*
635 ** Argument pVector points to a vector expression - either a TK_VECTOR
636 ** or TK_SELECT that returns more than one column. This function returns
637 ** the register number of a register that contains the value of
638 ** element iField of the vector.
639 **
640 ** If pVector is a TK_SELECT expression, then code for it must have
641 ** already been generated using the exprCodeSubselect() routine. In this
642 ** case parameter regSelect should be the first in an array of registers
643 ** containing the results of the sub-select.
644 **
645 ** If pVector is of type TK_VECTOR, then code for the requested field
646 ** is generated. In this case (*pRegFree) may be set to the number of
647 ** a temporary register to be freed by the caller before returning.
648 **
649 ** Before returning, output parameter (*ppExpr) is set to point to the
650 ** Expr object corresponding to element iElem of the vector.
651 */
659 ){
665 }
670 }
675 }
677 }
679 /*
680 ** Expression pExpr is a comparison between two vector values. Compute
681 ** the result of the comparison (1, 0, or NULL) and write that
682 ** result into register dest.
683 **
684 ** The caller must satisfy the following preconditions:
685 **
686 ** if pExpr->op==TK_IS: op==TK_EQ and p5==SQLITE_NULLEQ
687 ** if pExpr->op==TK_ISNOT: op==TK_NE and p5==SQLITE_NULLEQ
688 ** otherwise: op==pExpr->op and p5==0
689 */
695 u8 p5 /* SQLITE_NULLEQ or zero */
696 ){
714 }
719 );
755 }
760 }
763 }
770 }
771 }
776 }
777 }
779 #if SQLITE_MAX_EXPR_DEPTH>0
780 /*
781 ** Check that argument nHeight is less than or equal to the maximum
782 ** expression depth allowed. If it is not, leave an error message in
783 ** pParse.
784 */
791 );
793 }
795 }
797 /* The following three functions, heightOfExpr(), heightOfExprList()
798 ** and heightOfSelect(), are used to determine the maximum height
799 ** of any expression tree referenced by the structure passed as the
800 ** first argument.
801 **
802 ** If this maximum height is greater than the current value pointed
803 ** to by pnHeight, the second parameter, then set *pnHeight to that
804 ** value.
805 */
810 }
811 }
812 }
818 }
819 }
820 }
830 }
831 }
833 /*
834 ** Set the Expr.nHeight variable in the structure passed as an
835 ** argument. An expression with no children, Expr.pList or
836 ** Expr.pSelect member has a height of 1. Any other expression
837 ** has a height equal to the maximum height of any other
838 ** referenced Expr plus one.
839 **
840 ** Also propagate EP_Propagate flags up from Expr.x.pList to Expr.flags,
841 ** if appropriate.
842 */
847 }
853 }
855 }
857 /*
858 ** Set the Expr.nHeight variable using the exprSetHeight() function. If
859 ** the height is greater than the maximum allowed expression depth,
860 ** leave an error in pParse.
861 **
862 ** Also propagate all EP_Propagate flags from the Expr.x.pList into
863 ** Expr.flags.
864 */
869 }
871 /*
872 ** Return the maximum height of any expression tree referenced
873 ** by the select statement passed as an argument.
874 */
879 }
881 /*
882 ** Propagate all EP_Propagate flags from the Expr.x.pList into
883 ** Expr.flags.
884 */
889 }
890 }
891 #define exprSetHeight(y)
894 /*
895 ** Set the error offset for an Expr node, if possible.
896 */
901 }
903 /*
904 ** This routine is the core allocator for Expr nodes.
905 **
906 ** Construct a new expression node and return a pointer to it. Memory
907 ** for this node and for the pToken argument is a single allocation
908 ** obtained from sqlite3DbMalloc(). The calling function
909 ** is responsible for making sure the node eventually gets freed.
910 **
911 ** If dequote is true, then the token (if it exists) is dequoted.
912 ** If dequote is false, no dequoting is performed. The deQuote
913 ** parameter is ignored if pToken is NULL or if the token does not
914 ** appear to be quoted. If the quotes were of the form "..." (double-quotes)
915 ** then the EP_DblQuoted flag is set on the expression node.
916 **
917 ** Special case: If op==TK_INTEGER and pToken points to a string that
918 ** can be translated into a 32-bit integer, then the token is not
919 ** stored in u.zToken. Instead, the integer values is written
920 ** into u.iValue and the EP_IntValue flag is set. No extra storage
921 ** is allocated to hold the integer text and the dequote flag is ignored.
922 */
928 ){
939 }
940 }
957 }
958 }
959 }
960 #if SQLITE_MAX_EXPR_DEPTH>0
962 #endif
963 }
965 }
967 /*
968 ** Allocate a new expression node from a zero-terminated token that has
969 ** already been dequoted.
970 */
975 ){
976 Token x;
980 }
982 /*
983 ** Attach subtrees pLeft and pRight to the Expr node pRoot.
984 **
985 ** If pRoot==NULL that means that a memory allocation error has occurred.
986 ** In that case, delete the subtrees pLeft and pRight.
987 */
992 Expr *pRight
993 ){
1004 #if SQLITE_MAX_EXPR_DEPTH>0
1008 #endif
1009 }
1013 #if SQLITE_MAX_EXPR_DEPTH>0
1016 }
1017 #endif
1018 }
1019 }
1020 }
1022 /*
1023 ** Allocate an Expr node which joins as many as two subtrees.
1024 **
1025 ** One or both of the subtrees can be NULL. Return a pointer to the new
1026 ** Expr node. Or, if an OOM error occurs, set pParse->db->mallocFailed,
1027 ** free the subtrees and return NULL.
1028 */
1034 ){
1046 }
1048 }
1050 /*
1051 ** Add pSelect to the Expr.x.pSelect field. Or, if pExpr is NULL (due
1052 ** do a memory allocation failure) then delete the pSelect object.
1053 */
1062 }
1063 }
1065 /*
1066 ** Expression list pEList is a list of vector values. This function
1067 ** converts the contents of pEList to a VALUES(...) Select statement
1068 ** returning 1 row for each element of the list. For example, the
1069 ** expression list:
1070 **
1071 ** ( (1,2), (3,4) (5,6) )
1072 **
1073 ** is translated to the equivalent of:
1074 **
1075 ** VALUES(1,2), (3,4), (5,6)
1076 **
1077 ** Each of the vector values in pEList must contain exactly nElem terms.
1078 ** If a list element that is not a vector or does not contain nElem terms,
1079 ** an error message is left in pParse.
1080 **
1081 ** This is used as part of processing IN(...) expressions with a list
1082 ** of vectors on the RHS. e.g. "... IN ((1,2), (3,4), (5,6))".
1083 */
1097 }
1101 );
1103 }
1111 }
1113 }
1114 }
1118 }
1121 }
1123 /*
1124 ** Join two expressions using an AND operator. If either expression is
1125 ** NULL, then just return the other expression.
1126 **
1127 ** If one side or the other of the AND is known to be false, and neither side
1128 ** is part of an ON clause, then instead of returning an AND expression,
1129 ** just return a constant expression with a value of false.
1130 */
1140 && !IN_RENAME_OBJECT
1141 ){
1147 }
1148 }
1149 }
1151 /*
1152 ** Construct a new expression node for a function with multiple
1153 ** arguments.
1154 */
1160 ){
1168 }
1174 ){
1176 }
1183 }
1185 /*
1186 ** Report an error when attempting to use an ORDER BY clause within
1187 ** the arguments of a non-aggregate function.
1188 */
1192 );
1193 }
1195 /*
1196 ** Attach an ORDER BY clause to a function call.
1197 **
1198 ** functionname( arguments ORDER BY sortlist )
1199 ** \_____________________/ \______/
1200 ** pExpr pOrderBy
1201 **
1202 ** The ORDER BY clause is inserted into a new Expr node of type TK_ORDER
1203 ** and added to the Expr.pLeft field of the parent TK_FUNCTION node.
1204 */
1209 ){
1215 }
1220 }
1225 /* Ignore ORDER BY on zero-argument aggregates */
1228 pOrderBy);
1230 }
1235 }
1241 }
1246 }
1248 /*
1249 ** Check to see if a function is usable according to current access
1250 ** rules:
1251 **
1252 ** SQLITE_FUNC_DIRECT - Only usable from top-level SQL
1253 **
1254 ** SQLITE_FUNC_UNSAFE - Usable if TRUSTED_SCHEMA or from
1255 ** top-level SQL
1256 **
1257 ** If the function is not usable, create an error.
1258 */
1263 ){
1269 ){
1270 /* Functions prohibited in triggers and views if:
1271 ** (1) tagged with SQLITE_DIRECTONLY
1272 ** (2) not tagged with SQLITE_INNOCUOUS (which means it
1273 ** is tagged with SQLITE_FUNC_UNSAFE) and
1274 ** SQLITE_DBCONFIG_TRUSTED_SCHEMA is off (meaning
1275 ** that the schema is possibly tainted).
1276 */
1278 }
1279 }
1280 }
1282 /*
1283 ** Assign a variable number to an expression that encodes a wildcard
1284 ** in the original SQL statement.
1285 **
1286 ** Wildcards consisting of a single "?" are assigned the next sequential
1287 ** variable number.
1288 **
1289 ** Wildcards of the form "?nnn" are assigned the number "nnn". We make
1290 ** sure "nnn" is not too big to avoid a denial of service attack when
1291 ** the SQL statement comes from an external source.
1292 **
1293 ** Wildcards of the form ":aaa", "@aaa", or "$aaa" are assigned the same number
1294 ** as the previous instance of the same wildcard. Or if this is the first
1295 ** instance of the wildcard, the next sequential variable number is
1296 ** assigned.
1297 */
1301 ynVar x;
1310 /* Wildcard of the form "?". Assign the next variable number */
1316 /* Wildcard of the form "?nnn". Convert "nnn" to an integer and
1317 ** use it as the variable number */
1318 i64 i;
1325 }
1335 }
1342 }
1344 /* Wildcards like ":aaa", "$aaa" or "@aaa". Reuse the same variable
1345 ** number as the prior appearance of the same name, or if the name
1346 ** has never appeared before, reuse the same variable number
1347 */
1352 }
1353 }
1356 }
1357 }
1362 }
1363 }
1365 /*
1366 ** Recursively delete an expression tree.
1367 */
1375 #ifdef SQLITE_DEBUG
1381 }
1382 #endif
1384 /* The Expr.x union is never used at the same time as Expr.pRight */
1395 #ifndef SQLITE_OMIT_WINDOWFUNC
1398 }
1399 #endif
1400 }
1401 }
1404 }
1405 }
1408 }
1410 /*
1411 ** Clear both elements of an OnOrUsing object
1412 */
1415 /* Nothing to clear */
1420 }
1421 }
1423 /*
1424 ** Arrange to cause pExpr to be deleted when the pParse is deleted.
1425 ** This is similar to sqlite3ExprDelete() except that the delete is
1426 ** deferred until the pParse is deleted.
1427 **
1428 ** The pExpr might be deleted immediately on an OOM error.
1429 **
1430 ** The deferred delete is (currently) implemented by adding the
1431 ** pExpr to the pParse->pConstExpr list with a register number of 0.
1432 */
1436 pExpr);
1437 }
1439 /* Invoke sqlite3RenameExprUnmap() and sqlite3ExprDelete() on the
1440 ** expression.
1441 */
1446 }
1448 }
1449 }
1451 /*
1452 ** Return the number of bytes allocated for the expression structure
1453 ** passed as the first argument. This is always one of EXPR_FULLSIZE,
1454 ** EXPR_REDUCEDSIZE or EXPR_TOKENONLYSIZE.
1455 */
1460 }
1462 /*
1463 ** The dupedExpr*Size() routines each return the number of bytes required
1464 ** to store a copy of an expression or expression tree. They differ in
1465 ** how much of the tree is measured.
1466 **
1467 ** dupedExprStructSize() Size of only the Expr structure
1468 ** dupedExprNodeSize() Size of Expr + space for token
1469 ** dupedExprSize() Expr + token + subtree components
1470 **
1471 ***************************************************************************
1472 **
1473 ** The dupedExprStructSize() function returns two values OR-ed together:
1474 ** (1) the space required for a copy of the Expr structure only and
1475 ** (2) the EP_xxx flags that indicate what the structure size should be.
1476 ** The return values is always one of:
1477 **
1478 ** EXPR_FULLSIZE
1479 ** EXPR_REDUCEDSIZE | EP_Reduced
1480 ** EXPR_TOKENONLYSIZE | EP_TokenOnly
1481 **
1482 ** The size of the structure can be found by masking the return value
1483 ** of this routine with 0xfff. The flags can be found by masking the
1484 ** return value with EP_Reduced|EP_TokenOnly.
1485 **
1486 ** Note that with flags==EXPRDUP_REDUCE, this routines works on full-size
1487 ** (unreduced) Expr objects as they or originally constructed by the parser.
1488 ** During expression analysis, extra information is computed and moved into
1489 ** later parts of the Expr object and that extra information might get chopped
1490 ** off if the expression is reduced. Note also that it does not work to
1491 ** make an EXPRDUP_REDUCE copy of a reduced expression. It is only legal
1492 ** to reduce a pristine expression tree from the parser. The implementation
1493 ** of dupedExprStructSize() contain multiple assert() statements that attempt
1494 ** to enforce this constraint.
1495 */
1512 }
1513 }
1515 }
1517 /*
1518 ** This function returns the space in bytes required to store the copy
1519 ** of the Expr structure and a copy of the Expr.u.zToken string (if that
1520 ** string is defined.)
1521 */
1526 }
1528 }
1530 /*
1531 ** Return the number of bytes required to create a duplicate of the
1532 ** expression passed as the first argument.
1533 **
1534 ** The value returned includes space to create a copy of the Expr struct
1535 ** itself and the buffer referred to by Expr.u.zToken, if any.
1536 **
1537 ** The return value includes space to duplicate all Expr nodes in the
1538 ** tree formed by Expr.pLeft and Expr.pRight, but not any other
1539 ** substructure such as Expr.x.pList, Expr.x.pSelect, and Expr.y.pWin.
1540 */
1549 }
1551 /*
1552 ** An EdupBuf is a memory allocation used to stored multiple Expr objects
1553 ** together with their Expr.zToken content. This is used to help implement
1554 ** compression while doing sqlite3ExprDup(). The top-level Expr does the
1555 ** allocation for itself and many of its decendents, then passes an instance
1556 ** of the structure down into exprDup() so that they decendents can have
1557 ** access to that memory.
1558 */
1562 #ifdef SQLITE_DEBUG
1564 #endif
1565 };
1567 /*
1568 ** This function is similar to sqlite3ExprDup(), except that if pEdupBuf
1569 ** is not NULL then it points to memory that can be used to store a copy
1570 ** of the input Expr p together with its p->u.zToken (if any). pEdupBuf
1571 ** is updated with the new buffer tail prior to returning.
1572 */
1578 ){
1589 /* Figure out where to write the new Expr structure. */
1592 #ifdef SQLITE_DEBUG
1594 #endif
1608 }
1611 #ifdef SQLITE_DEBUG
1613 #endif
1616 }
1621 /* Set nNewSize to the size allocated for the structure pointed to
1622 ** by pNew. This is either EXPR_FULLSIZE, EXPR_REDUCEDSIZE or
1623 ** EXPR_TOKENONLYSIZE. nToken is set to the number of bytes consumed
1624 ** by the copy of the p->u.zToken string (if any).
1625 */
1633 }
1634 }
1646 }
1648 }
1650 /* Set the EP_Reduced, EP_TokenOnly, and EP_Static flags appropriately. */
1657 }
1659 /* Copy the p->u.zToken string, if any. */
1665 }
1670 /* Fill in the pNew->x.pSelect or pNew->x.pList member. */
1676 }
1678 #ifndef SQLITE_OMIT_WINDOWFUNC
1682 }
1685 /* Fill in pNew->pLeft and pNew->pRight. */
1695 }
1706 }
1708 }
1709 }
1710 }
1714 }
1716 /*
1717 ** Create and return a deep copy of the object passed as the second
1718 ** argument. If an OOM condition is encountered, NULL is returned
1719 ** and the db->mallocFailed flag set.
1720 */
1721 #ifndef SQLITE_OMIT_CTE
1735 }
1736 }
1737 }
1739 }
1740 #else
1741 # define sqlite3WithDup(x,y) 0
1742 #endif
1744 #ifndef SQLITE_OMIT_WINDOWFUNC
1745 /*
1746 ** The gatherSelectWindows() procedure and its helper routine
1747 ** gatherSelectWindowsCallback() are used to scan all the expressions
1748 ** an a newly duplicated SELECT statement and gather all of the Window
1749 ** objects found there, assembling them onto the linked list at Select->pWin.
1750 */
1759 }
1761 }
1764 }
1766 Walker w;
1773 }
1774 #endif
1777 /*
1778 ** The following group of routines make deep copies of expressions,
1779 ** expression lists, ID lists, and select statements. The copies can
1780 ** be deleted (by being passed to their respective ...Delete() routines)
1781 ** without effecting the originals.
1782 **
1783 ** The expression list, ID, and source lists return by sqlite3ExprListDup(),
1784 ** sqlite3IdListDup(), and sqlite3SrcListDup() can not be further expanded
1785 ** by subsequent calls to sqlite*ListAppend() routines.
1786 **
1787 ** Any tables that the SrcList might point to are not duplicated.
1788 **
1789 ** The flags parameter contains a combination of the EXPRDUP_XXX flags.
1790 ** If the EXPRDUP_REDUCE flag is set, then the structure returned is a
1791 ** truncated version of the usual Expr structure that will be stored as
1792 ** part of the in-memory representation of the database schema.
1793 */
1797 }
1820 ){
1830 }
1832 }
1833 }
1838 }
1840 }
1842 /*
1843 ** If cursors, triggers, views and subqueries are all omitted from
1844 ** the build, then none of the following routines, except for
1845 ** sqlite3SelectDup(), can be called. sqlite3SelectDup() is sometimes
1846 ** called with a NULL argument.
1847 */
1848 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) \
1849 || !defined(SQLITE_OMIT_SUBQUERY)
1874 }
1878 }
1882 }
1886 }
1893 }
1895 }
1897 }
1913 }
1915 }
1943 #ifndef SQLITE_OMIT_WINDOWFUNC
1947 #endif
1950 /* Any prior OOM might have left the Select object incomplete.
1951 ** Delete the whole thing rather than allow an incomplete Select
1952 ** to be used by the code generator. */
1956 }
1960 }
1963 }
1964 #else
1968 }
1969 #endif
1972 /*
1973 ** Add a new element to the end of an expression list. If pList is
1974 ** initially NULL, then create a new expression list.
1975 **
1976 ** The pList argument must be either NULL or a pointer to an ExprList
1977 ** obtained from a prior call to sqlite3ExprListAppend().
1978 **
1979 ** If a memory allocation error occurs, the entire list is freed and
1980 ** NULL is returned. If non-NULL is returned, then it is guaranteed
1981 ** that the new entry was successfully appended.
1982 */
1987 ){
1995 }
2002 }
2007 ){
2019 }
2024 }
2029 ){
2033 }
2036 }
2041 }
2043 /*
2044 ** pColumns and pExpr form a vector assignment which is part of the SET
2045 ** clause of an UPDATE statement. Like this:
2046 **
2047 ** (a,b,c) = (expr1,expr2,expr3)
2048 ** Or: (a,b,c) = (SELECT x,y,z FROM ....)
2049 **
2050 ** For each term of the vector assignment, append new entries to the
2051 ** expression list pList. In the case of a subquery on the RHS, append
2052 ** TK_SELECT_COLUMN expressions.
2053 */
2059 ){
2064 /* pColumns can only be NULL due to an OOM but an OOM will cause an
2065 ** exit prior to this routine being invoked */
2069 /* If the RHS is a vector, then we can immediately check to see that
2070 ** the size of the RHS and LHS match. But if the RHS is a SELECT,
2071 ** wildcards ("*") in the result set of the SELECT must be expanded before
2072 ** we can do the size check, so defer the size check until code generation.
2073 */
2078 }
2089 }
2090 }
2097 /* Store the SELECT statement in pRight so it will be deleted when
2098 ** sqlite3ExprListDelete() is called */
2102 /* Remember the size of the LHS in iTable so that we can check that
2103 ** the RHS and LHS sizes match during code generation. */
2105 }
2107 vector_append_error:
2111 }
2113 /*
2114 ** Set the sort order for the last element on the given ExprList.
2115 */
2125 );
2129 );
2135 }
2142 }
2143 }
2144 }
2146 /*
2147 ** Set the ExprList.a[].zEName element of the most recently added item
2148 ** on the expression list.
2149 **
2150 ** pList might be NULL following an OOM error. But pName should never be
2151 ** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag
2152 ** is set.
2153 */
2159 ){
2170 /* If dequote==0, then pName->z does not point to part of a DDL
2171 ** statement handled by the parser. And so no token need be added
2172 ** to the token-map. */
2176 }
2177 }
2178 }
2179 }
2181 /*
2182 ** Set the ExprList.a[].zSpan element of the most recently added item
2183 ** on the expression list.
2184 **
2185 ** pList might be NULL following an OOM error. But pSpan should never be
2186 ** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag
2187 ** is set.
2188 */
2194 ){
2203 }
2204 }
2205 }
2207 /*
2208 ** If the expression list pEList contains more than iLimit elements,
2209 ** leave an error message in pParse.
2210 */
2215 ){
2221 }
2222 }
2224 /*
2225 ** Delete an entire expression list.
2226 */
2235 pItem++;
2238 }
2241 }
2243 /*
2244 ** Return the bitwise-OR of all Expr.flags fields in the given
2245 ** ExprList.
2246 */
2255 }
2257 }
2259 /*
2260 ** This is a SELECT-node callback for the expression walker that
2261 ** always "fails". By "fail" in this case, we mean set
2262 ** pWalker->eCode to zero and abort.
2263 **
2264 ** This callback is used by multiple expression walkers.
2265 */
2270 }
2272 /*
2273 ** Check the input string to see if it is "true" or "false" (in any case).
2274 **
2275 ** If the string is.... Return
2276 ** "true" EP_IsTrue
2277 ** "false" EP_IsFalse
2278 ** anything else 0
2279 */
2284 }
2287 /*
2288 ** If the input expression is an ID with the name "true" or "false"
2289 ** then convert it into an TK_TRUEFALSE term. Return non-zero if
2290 ** the conversion happened, and zero if the expression is unaltered.
2291 */
2293 u32 v;
2297 ){
2301 }
2303 }
2305 /*
2306 ** The argument must be a TK_TRUEFALSE Expr node. Return 1 if it is TRUE
2307 ** and 0 if it is FALSE.
2308 */
2316 }
2318 /*
2319 ** If pExpr is an AND or OR expression, try to simplify it by eliminating
2320 ** terms that are always true or false. Return the simplified expression.
2321 ** Or return the original expression if no simplification is possible.
2322 **
2323 ** Examples:
2324 **
2325 ** (x<10) AND true => (x<10)
2326 ** (x<10) AND false => false
2327 ** (x<10) AND (y=22 OR false) => (x<10) AND (y=22)
2328 ** (x<10) AND (y=22 OR true) => (x<10)
2329 ** (y=22) OR true => true
2330 */
2340 }
2341 }
2343 }
2346 /*
2347 ** These routines are Walker callbacks used to check expressions to
2348 ** see if they are "constant" for some definition of constant. The
2349 ** Walker.eCode value determines the type of "constant" we are looking
2350 ** for.
2351 **
2352 ** These callback routines are used to implement the following:
2353 **
2354 ** sqlite3ExprIsConstant() pWalker->eCode==1
2355 ** sqlite3ExprIsConstantNotJoin() pWalker->eCode==2
2356 ** sqlite3ExprIsTableConstant() pWalker->eCode==3
2357 ** sqlite3ExprIsConstantOrFunction() pWalker->eCode==4 or 5
2358 **
2359 ** In all cases, the callbacks set Walker.eCode=0 and abort if the expression
2360 ** is found to not be a constant.
2361 **
2362 ** The sqlite3ExprIsConstantOrFunction() is used for evaluating DEFAULT
2363 ** expressions in a CREATE TABLE statement. The Walker.eCode value is 5
2364 ** when parsing an existing schema out of the sqlite_schema table and 4
2365 ** when processing a new CREATE TABLE statement. A bound parameter raises
2366 ** an error for new statements, but is silently converted
2367 ** to NULL for existing schemas. This allows sqlite_schema tables that
2368 ** contain a bound parameter because they were generated by older versions
2369 ** of SQLite to be parsed by newer versions of SQLite without raising a
2370 ** malformed schema error.
2371 */
2374 /* If pWalker->eCode is 2 then any term of the expression that comes from
2375 ** the ON or USING clauses of an outer join disqualifies the expression
2376 ** from being considered constant. */
2380 }
2383 /* Consider functions to be constant if all their arguments are constant
2384 ** and either pWalker->eCode==4 or 5 or the function has the
2385 ** SQLITE_FUNC_CONST flag. */
2389 ){
2395 }
2397 /* Convert "true" or "false" in a DEFAULT clause into the
2398 ** appropriate TK_TRUEFALSE operator */
2401 }
2402 /* no break */ deliberate_fall_through
2412 }
2415 }
2416 /* no break */ deliberate_fall_through
2427 /* Silently convert bound parameters that appear inside of CREATE
2428 ** statements into a NULL when parsing the CREATE statement text out
2429 ** of the sqlite_schema table */
2432 /* A bound parameter in a CREATE statement that originates from
2433 ** sqlite3_prepare() causes an error */
2436 }
2437 /* no break */ deliberate_fall_through
2442 }
2443 }
2445 Walker w;
2449 #ifdef SQLITE_DEBUG
2451 #endif
2455 }
2457 /*
2458 ** Walk an expression tree. Return non-zero if the expression is constant
2459 ** and 0 if it involves variables or function calls.
2460 **
2461 ** For the purposes of this function, a double-quoted string (ex: "abc")
2462 ** is considered a variable but a single-quoted string (ex: 'abc') is
2463 ** a constant.
2464 */
2467 }
2469 /*
2470 ** Walk an expression tree. Return non-zero if
2471 **
2472 ** (1) the expression is constant, and
2473 ** (2) the expression does originate in the ON or USING clause
2474 ** of a LEFT JOIN, and
2475 ** (3) the expression does not contain any EP_FixedCol TK_COLUMN
2476 ** operands created by the constant propagation optimization.
2477 **
2478 ** When this routine returns true, it indicates that the expression
2479 ** can be added to the pParse->pConstExpr list and evaluated once when
2480 ** the prepared statement starts up. See sqlite3ExprCodeRunJustOnce().
2481 */
2484 }
2486 /*
2487 ** Walk an expression tree. Return non-zero if the expression is constant
2488 ** for any single row of the table with cursor iCur. In other words, the
2489 ** expression must not refer to any non-deterministic function nor any
2490 ** table other than iCur.
2491 */
2494 }
2496 /*
2497 ** Check pExpr to see if it is an constraint on the single data source
2498 ** pSrc = &pSrcList->a[iSrc]. In other words, check to see if pExpr
2499 ** constrains pSrc but does not depend on any other tables or data
2500 ** sources anywhere else in the query. Return true (non-zero) if pExpr
2501 ** is a constraint on pSrc only.
2502 **
2503 ** This is an optimization. False negatives will perhaps cause slower
2504 ** queries, but false positives will yield incorrect answers. So when in
2505 ** doubt, return 0.
2506 **
2507 ** To be an single-source constraint, the following must be true:
2508 **
2509 ** (1) pExpr cannot refer to any table other than pSrc->iCursor.
2510 **
2511 ** (2) pExpr cannot use subqueries or non-deterministic functions.
2512 **
2513 ** (3) pSrc cannot be part of the left operand for a RIGHT JOIN.
2514 ** (Is there some way to relax this constraint?)
2515 **
2516 ** (4) If pSrc is the right operand of a LEFT JOIN, then...
2517 ** (4a) pExpr must come from an ON clause..
2518 ** (4b) and specifically the ON clause associated with the LEFT JOIN.
2519 **
2520 ** (5) If pSrc is not the right operand of a LEFT JOIN or the left
2521 ** operand of a RIGHT JOIN, then pExpr must be from the WHERE
2522 ** clause, not an ON clause.
2523 **
2524 ** (6) Either:
2525 **
2526 ** (6a) pExpr does not originate in an ON or USING clause, or
2527 **
2528 ** (6b) The ON or USING clause from which pExpr is derived is
2529 ** not to the left of a RIGHT JOIN (or FULL JOIN).
2530 **
2531 ** Without this restriction, accepting pExpr as a single-table
2532 ** constraint might move the the ON/USING filter expression
2533 ** from the left side of a RIGHT JOIN over to the right side,
2534 ** which leads to incorrect answers. See also restriction (9)
2535 ** on push-down.
2536 */
2541 ){
2545 }
2551 }
2554 ){
2560 }
2562 }
2563 }
2564 }
2566 }
2569 /*
2570 ** sqlite3WalkExpr() callback used by sqlite3ExprIsConstantOrGroupBy().
2571 */
2576 /* Check if pExpr is identical to any GROUP BY term. If so, consider
2577 ** it constant. */
2584 }
2585 }
2586 }
2588 /* Check if pExpr is a sub-select. If so, consider it variable. */
2592 }
2595 }
2597 /*
2598 ** Walk the expression tree passed as the first argument. Return non-zero
2599 ** if the expression consists entirely of constants or copies of terms
2600 ** in pGroupBy that sort with the BINARY collation sequence.
2601 **
2602 ** This routine is used to determine if a term of the HAVING clause can
2603 ** be promoted into the WHERE clause. In order for such a promotion to work,
2604 ** the value of the HAVING clause term must be the same for all members of
2605 ** a "group". The requirement that the GROUP BY term must be BINARY
2606 ** assumes that no other collating sequence will have a finer-grained
2607 ** grouping than binary. In other words (A=B COLLATE binary) implies
2608 ** A=B in every other collating sequence. The requirement that the
2609 ** GROUP BY be BINARY is stricter than necessary. It would also work
2610 ** to promote HAVING clauses that use the same alternative collating
2611 ** sequence as the GROUP BY term, but that is much harder to check,
2612 ** alternative collating sequences are uncommon, and this is only an
2613 ** optimization, so we take the easy way out and simply require the
2614 ** GROUP BY to use the BINARY collating sequence.
2615 */
2617 Walker w;
2625 }
2627 /*
2628 ** Walk an expression tree for the DEFAULT field of a column definition
2629 ** in a CREATE TABLE statement. Return non-zero if the expression is
2630 ** acceptable for use as a DEFAULT. That is to say, return non-zero if
2631 ** the expression is constant or a function call with constant arguments.
2632 ** Return and 0 if there are any variables.
2633 **
2634 ** isInit is true when parsing from sqlite_schema. isInit is false when
2635 ** processing a new CREATE TABLE statement. When isInit is true, parameters
2636 ** (such as ? or $abc) in the expression are converted into NULL. When
2637 ** isInit is false, parameters raise an error. Parameters should not be
2638 ** allowed in a CREATE TABLE statement, but some legacy versions of SQLite
2639 ** allowed it, so we need to support it when reading sqlite_schema for
2640 ** backwards compatibility.
2641 **
2642 ** If isInit is true, set EP_FromDDL on every TK_FUNCTION node.
2643 **
2644 ** For the purposes of this function, a double-quoted string (ex: "abc")
2645 ** is considered a variable but a single-quoted string (ex: 'abc') is
2646 ** a constant.
2647 */
2651 }
2653 #ifdef SQLITE_ENABLE_CURSOR_HINTS
2654 /*
2655 ** Walk an expression tree. Return 1 if the expression contains a
2656 ** subquery of some kind. Return 0 if there are no subqueries.
2657 */
2659 Walker w;
2663 #ifdef SQLITE_DEBUG
2665 #endif
2668 }
2669 #endif
2671 /*
2672 ** If the expression p codes a constant integer that is small enough
2673 ** to fit in a 32-bit integer, return 1 and put the value of the integer
2674 ** in *pValue. If the expression is not an integer or if it is too big
2675 ** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged.
2676 */
2681 /* If an expression is an integer literal that fits in a signed 32-bit
2682 ** integer, then the EP_IntValue flag will have already been set */
2689 }
2694 }
2701 }
2703 }
2705 }
2707 }
2709 /*
2710 ** Return FALSE if there is no chance that the expression can be NULL.
2711 **
2712 ** If the expression might be NULL or if the expression is too complex
2713 ** to tell return TRUE.
2714 **
2715 ** This routine is used as an optimization, to skip OP_IsNull opcodes
2716 ** when we know that a value cannot be NULL. Hence, a false positive
2717 ** (returning TRUE when in fact the expression can never be NULL) might
2718 ** be a small performance hit but is otherwise harmless. On the other
2719 ** hand, a false negative (returning FALSE when the result could be NULL)
2720 ** will likely result in an incorrect answer. So when in doubt, return
2721 ** TRUE.
2722 */
2724 u8 op;
2729 }
2747 }
2748 }
2750 /*
2751 ** Return TRUE if the given expression is a constant which would be
2752 ** unchanged by OP_Affinity with the affinity given in the second
2753 ** argument.
2754 **
2755 ** This routine is used to determine if the OP_Affinity operation
2756 ** can be omitted. When in doubt return FALSE. A false negative
2757 ** is harmless. A false positive, however, can result in the wrong
2758 ** answer.
2759 */
2761 u8 op;
2767 }
2773 }
2776 }
2779 }
2782 }
2786 }
2789 }
2790 }
2791 }
2793 /*
2794 ** Return TRUE if the given string is a row-id column name.
2795 */
2801 }
2803 /*
2804 ** Return a pointer to a buffer containing a usable rowid alias for table
2805 ** pTab. An alias is usable if there is not an explicit user-defined column
2806 ** of the same name.
2807 */
2816 }
2819 }
2820 }
2822 }
2824 /*
2825 ** pX is the RHS of an IN operator. If pX is a SELECT statement
2826 ** that can be simplified to a direct table access, then return
2827 ** a pointer to the SELECT statement. If pX is not a SELECT statement,
2828 ** or if the SELECT statement needs to be materialized into a transient
2829 ** table, then return NULL.
2830 */
2831 #ifndef SQLITE_OMIT_SUBQUERY
2846 }
2860 /* All SELECT results must be columns. */
2865 }
2867 }
2870 #ifndef SQLITE_OMIT_SUBQUERY
2871 /*
2872 ** Generate code that checks the left-most column of index table iCur to see if
2873 ** it contains any NULL entries. Cause the register at regHasNull to be set
2874 ** to a non-NULL value if iCur contains no NULLs. Cause register regHasNull
2875 ** to be set to NULL if iCur contains one or more NULL values.
2876 */
2885 }
2886 #endif
2889 #ifndef SQLITE_OMIT_SUBQUERY
2890 /*
2891 ** The argument is an IN operator with a list (not a subquery) on the
2892 ** right-hand side. Return TRUE if that list is constant.
2893 */
2903 }
2904 #endif
2906 /*
2907 ** This function is used by the implementation of the IN (...) operator.
2908 ** The pX parameter is the expression on the RHS of the IN operator, which
2909 ** might be either a list of expressions or a subquery.
2910 **
2911 ** The job of this routine is to find or create a b-tree object that can
2912 ** be used either to test for membership in the RHS set or to iterate through
2913 ** all members of the RHS set, skipping duplicates.
2914 **
2915 ** A cursor is opened on the b-tree object that is the RHS of the IN operator
2916 ** and the *piTab parameter is set to the index of that cursor.
2917 **
2918 ** The returned value of this function indicates the b-tree type, as follows:
2919 **
2920 ** IN_INDEX_ROWID - The cursor was opened on a database table.
2921 ** IN_INDEX_INDEX_ASC - The cursor was opened on an ascending index.
2922 ** IN_INDEX_INDEX_DESC - The cursor was opened on a descending index.
2923 ** IN_INDEX_EPH - The cursor was opened on a specially created and
2924 ** populated ephemeral table.
2925 ** IN_INDEX_NOOP - No cursor was allocated. The IN operator must be
2926 ** implemented as a sequence of comparisons.
2927 **
2928 ** An existing b-tree might be used if the RHS expression pX is a simple
2929 ** subquery such as:
2930 **
2931 ** SELECT <column1>, <column2>... FROM <table>
2932 **
2933 ** If the RHS of the IN operator is a list or a more complex subquery, then
2934 ** an ephemeral table might need to be generated from the RHS and then
2935 ** pX->iTable made to point to the ephemeral table instead of an
2936 ** existing table. In this case, the creation and initialization of the
2937 ** ephemeral table might be put inside of a subroutine, the EP_Subrtn flag
2938 ** will be set on pX and the pX->y.sub fields will be set to show where
2939 ** the subroutine is coded.
2940 **
2941 ** The inFlags parameter must contain, at a minimum, one of the bits
2942 ** IN_INDEX_MEMBERSHIP or IN_INDEX_LOOP but not both. If inFlags contains
2943 ** IN_INDEX_MEMBERSHIP, then the generated table will be used for a fast
2944 ** membership test. When the IN_INDEX_LOOP bit is set, the IN index will
2945 ** be used to loop over all values of the RHS of the IN operator.
2946 **
2947 ** When IN_INDEX_LOOP is used (and the b-tree will be used to iterate
2948 ** through the set members) then the b-tree must not contain duplicates.
2949 ** An ephemeral table will be created unless the selected columns are guaranteed
2950 ** to be unique - either because it is an INTEGER PRIMARY KEY or due to
2951 ** a UNIQUE constraint or index.
2952 **
2953 ** When IN_INDEX_MEMBERSHIP is used (and the b-tree will be used
2954 ** for fast set membership tests) then an ephemeral table must
2955 ** be used unless <columns> is a single INTEGER PRIMARY KEY column or an
2956 ** index can be found with the specified <columns> as its left-most.
2957 **
2958 ** If the IN_INDEX_NOOP_OK and IN_INDEX_MEMBERSHIP are both set and
2959 ** if the RHS of the IN operator is a list (not a subquery) then this
2960 ** routine might decide that creating an ephemeral b-tree for membership
2961 ** testing is too expensive and return IN_INDEX_NOOP. In that case, the
2962 ** calling routine should implement the IN operator using a sequence
2963 ** of Eq or Ne comparison operations.
2964 **
2965 ** When the b-tree is being used for membership tests, the calling function
2966 ** might need to know whether or not the RHS side of the IN operator
2967 ** contains a NULL. If prRhsHasNull is not a NULL pointer and
2968 ** if there is any chance that the (...) might contain a NULL value at
2969 ** runtime, then a register is allocated and the register number written
2970 ** to *prRhsHasNull. If there is no chance that the (...) contains a
2971 ** NULL value, then *prRhsHasNull is left unchanged.
2972 **
2973 ** If a register is allocated and its location stored in *prRhsHasNull, then
2974 ** the value in that register will be NULL if the b-tree contains one or more
2975 ** NULL values, and it will be some non-NULL value if the b-tree contains no
2976 ** NULL values.
2977 **
2978 ** If the aiMap parameter is not NULL, it must point to an array containing
2979 ** one element for each column returned by the SELECT statement on the RHS
2980 ** of the IN(...) operator. The i'th entry of the array is populated with the
2981 ** offset of the index column that matches the i'th column returned by the
2982 ** SELECT. For example, if the expression and selected index are:
2983 **
2984 ** (?,?,?) IN (SELECT a, b, c FROM t1)
2985 ** CREATE INDEX i1 ON t1(b, c, a);
2986 **
2987 ** then aiMap[] is populated with {2, 0, 1}.
2988 */
2989 #ifndef SQLITE_OMIT_SUBQUERY
2997 ){
3008 /* If the RHS of this IN(...) operator is a SELECT, and if it matters
3009 ** whether or not the SELECT result contains NULL values, check whether
3010 ** or not NULL is actually possible (it may not be, for example, due
3011 ** to NOT NULL constraints in the schema). If no NULL values are possible,
3012 ** set prRhsHasNull to 0 before continuing. */
3018 }
3021 }
3022 }
3024 /* Check to see if an existing table or index can be used to
3025 ** satisfy the query. This is preferable to generating a new
3026 ** ephemeral table. */
3039 /* Code an OP_Transaction and OP_TableLock for <table>. */
3047 /* The "x IN (SELECT rowid FROM table)" case */
3061 /* Check that the affinity that will be used to perform each
3062 ** comparison is the same as the affinity of each column in table
3063 ** on the RHS of the IN operator. If it not, it is not possible to
3064 ** use any index of the RHS table. */
3076 /* sqlite3CompareAffinity() only returns TEXT if one side or the
3077 ** other has no affinity and the other side is TEXT. Hence,
3078 ** the only way for cmpaff to be TEXT is for idxaff to be TEXT
3079 ** and for the term on the LHS of the IN to have no affinity. */
3084 }
3085 }
3088 /* Search for an existing index that will work for this IN operator */
3094 /* Maximum nColumn is BMS-2, not BMS-1, so that we can compute
3095 ** BITMASK(nExpr) without overflowing */
3102 ){
3104 }
3105 }
3119 }
3121 }
3127 }
3131 /* If we reach this point, that means the index pIdx is usable */
3142 #ifdef SQLITE_ENABLE_COLUMN_USED_MASK
3146 #endif
3150 }
3151 }
3153 }
3159 /* If no preexisting index is available for the IN clause
3160 ** and IN_INDEX_NOOP is an allowed reply
3161 ** and the RHS of the IN operator is a list, not a subquery
3162 ** and the RHS is not constant or has two or fewer terms,
3163 ** then it is not worth creating an ephemeral table to evaluate
3164 ** the IN operator so return IN_INDEX_NOOP.
3165 */
3170 ){
3174 }
3177 /* Could not find an existing table or index to use as the RHS b-tree.
3178 ** We will have to generate an ephemeral table to do the job.
3179 */
3187 }
3192 }
3194 }
3200 }
3203 }
3204 #endif
3206 #ifndef SQLITE_OMIT_SUBQUERY
3207 /*
3208 ** Argument pExpr is an (?, ?...) IN(...) expression. This
3209 ** function allocates and returns a nul-terminated string containing
3210 ** the affinities to be used for each column of the comparison.
3211 **
3212 ** It is the responsibility of the caller to ensure that the returned
3213 ** string is eventually freed using sqlite3DbFree().
3214 */
3232 }
3233 }
3235 }
3237 }
3238 #endif
3240 #ifndef SQLITE_OMIT_SUBQUERY
3241 /*
3242 ** Load the Parse object passed as the first argument with an error
3243 ** message of the form:
3244 **
3245 ** "sub-select returns N columns - expected M"
3246 */
3251 }
3252 }
3253 #endif
3255 /*
3256 ** Expression pExpr is a vector that has been used in a context where
3257 ** it is not permitted. If pExpr is a sub-select vector, this routine
3258 ** loads the Parse object with a message of the form:
3259 **
3260 ** "sub-select returns N columns - expected 1"
3261 **
3262 ** Or, if it is a regular scalar vector:
3263 **
3264 ** "row value misused"
3265 */
3267 #ifndef SQLITE_OMIT_SUBQUERY
3271 #endif
3272 {
3274 }
3275 }
3277 #ifndef SQLITE_OMIT_SUBQUERY
3278 /*
3279 ** Generate code that will construct an ephemeral table containing all terms
3280 ** in the RHS of an IN operator. The IN operator can be in either of two
3281 ** forms:
3282 **
3283 ** x IN (4,5,11) -- IN operator with list on right-hand side
3284 ** x IN (SELECT a FROM b) -- IN operator with subquery on the right
3285 **
3286 ** The pExpr parameter is the IN operator. The cursor number for the
3287 ** constructed ephemeral table is returned. The first time the ephemeral
3288 ** table is computed, the cursor number is also stored in pExpr->iTable,
3289 ** however the cursor number returned might not be the same, as it might
3290 ** have been duplicated using OP_OpenDup.
3291 **
3292 ** If the LHS expression ("x" in the examples) is a column value, or
3293 ** the SELECT statement returns a column value, then the affinity of that
3294 ** column is used to build the index keys. If both 'x' and the
3295 ** SELECT... statement are columns, then numeric affinity is used
3296 ** if either column has NUMERIC or INTEGER affinity. If neither
3297 ** 'x' nor the SELECT... statement are columns, then numeric affinity
3298 ** is used.
3299 */
3304 ){
3315 /* The evaluation of the IN must be repeated every time it
3316 ** is encountered if any of the following is true:
3317 **
3318 ** * The right-hand side is a correlated subquery
3319 ** * The right-hand side is an expression list containing variables
3320 ** * We are inside a trigger
3321 **
3322 ** If all of the above are false, then we can compute the RHS just once
3323 ** and reuse it many names.
3324 */
3326 /* Reuse of the RHS is allowed */
3327 /* If this routine has already been coded, but the previous code
3328 ** might not have been invoked yet, so invoke it now as a subroutine.
3329 */
3335 }
3343 }
3345 /* Begin coding the subroutine */
3354 }
3356 /* Check to see if this is a vector IN operator */
3360 /* Construct the ephemeral table that will contain the content of
3361 ** RHS of the IN operator.
3362 */
3365 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
3370 }
3371 #endif
3375 /* Case 1: expr IN (SELECT ...)
3376 **
3377 ** Generate code to write the results of the select into the temporary
3378 ** table allocated and opened above.
3379 */
3385 ));
3386 /* If the LHS and RHS of the IN operator do not match, that
3387 ** error will have been caught long before we reach this point. */
3390 SelectDest dest;
3405 }
3414 );
3415 }
3416 }
3418 /* Case 2: expr IN (exprlist)
3419 **
3420 ** For each expression, build an index key from the evaluation and
3421 ** store it in the temporary table. If <expr> is a column, then use
3422 ** that columns affinity when building index keys. If <expr> is not
3423 ** a column, use numeric affinity.
3424 */
3435 }
3439 }
3441 /* Loop through each expression in <exprlist>. */
3447 /* If the expression is not constant then we will need to
3448 ** disable the test that was generated above that makes sure
3449 ** this code only executes once. Because for a non-constant
3450 ** expression we need to rerun this code each time.
3451 */
3457 }
3459 /* Evaluate the expression and insert it into the temp table */
3463 }
3466 }
3469 }
3473 /* Subroutine return */
3481 }
3482 }
3485 /*
3486 ** Generate code for scalar subqueries used as a subquery expression
3487 ** or EXISTS operator:
3488 **
3489 ** (SELECT a FROM b) -- subquery
3490 ** EXISTS (SELECT a FROM b) -- EXISTS subquery
3491 **
3492 ** The pExpr parameter is the SELECT or EXISTS operator to be coded.
3493 **
3494 ** Return the register that holds the result. For a multi-column SELECT,
3495 ** the result is stored in a contiguous array of registers and the
3496 ** return value is the register of the left-most result column.
3497 ** Return 0 if an error occurs.
3498 */
3499 #ifndef SQLITE_OMIT_SUBQUERY
3507 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
3509 #endif
3520 /* If this routine has already been coded, then invoke it as a
3521 ** subroutine. */
3528 }
3530 /* Begin coding the subroutine */
3538 /* The evaluation of the EXISTS/SELECT must be repeated every time it
3539 ** is encountered if any of the following is true:
3540 **
3541 ** * The right-hand side is a correlated subquery
3542 ** * The right-hand side is an expression list containing variables
3543 ** * We are inside a trigger
3544 **
3545 ** If all of the above are false, then we can run this code just once
3546 ** save the results, and reuse the same result on subsequent invocations.
3547 */
3550 }
3552 /* For a SELECT, generate code to put the values for all columns of
3553 ** the first row into an array of registers and return the index of
3554 ** the first register.
3555 **
3556 ** If this is an EXISTS, write an integer 0 (not exists) or 1 (exists)
3557 ** into a register and return that register number.
3558 **
3559 ** In both cases, the query is augmented with "LIMIT 1". Any
3560 ** preexisting limit is discarded in place of the new LIMIT 1.
3561 */
3578 }
3580 /* The subquery already has a limit. If the pre-existing limit is X
3581 ** then make the new limit X<>0 so that the new limit is either 1 or 0 */
3588 }
3592 /* If there is no pre-existing limit add a limit of 1 */
3595 }
3601 }
3606 }
3609 /* Subroutine return */
3618 }
3621 #ifndef SQLITE_OMIT_SUBQUERY
3622 /*
3623 ** Expr pIn is an IN(...) expression. This function checks that the
3624 ** sub-select on the RHS of the IN() operator has the same number of
3625 ** columns as the vector on the LHS. Or, if the RHS of the IN() is not
3626 ** a sub-query, that the LHS is a vector of size 1.
3627 */
3634 }
3638 }
3640 }
3641 #endif
3643 #ifndef SQLITE_OMIT_SUBQUERY
3644 /*
3645 ** Generate code for an IN expression.
3646 **
3647 ** x IN (SELECT ...)
3648 ** x IN (value, value, ...)
3649 **
3650 ** The left-hand side (LHS) is a scalar or vector expression. The
3651 ** right-hand side (RHS) is an array of zero or more scalar values, or a
3652 ** subquery. If the RHS is a subquery, the number of result columns must
3653 ** match the number of columns in the vector on the LHS. If the RHS is
3654 ** a list of values, the LHS must be a scalar.
3655 **
3656 ** The IN operator is true if the LHS value is contained within the RHS.
3657 ** The result is false if the LHS is definitely not in the RHS. The
3658 ** result is NULL if the presence of the LHS in the RHS cannot be
3659 ** determined due to NULLs.
3660 **
3661 ** This routine generates code that jumps to destIfFalse if the LHS is not
3662 ** contained within the RHS. If due to NULLs we cannot determine if the LHS
3663 ** is contained in the RHS then jump to destIfNull. If the LHS is contained
3664 ** within the RHS then fall through.
3665 **
3666 ** See the separate in-operator.md documentation file in the canonical
3667 ** SQLite source tree for additional information.
3668 */
3674 ){
3701 );
3704 /* Attempt to compute the RHS. After this step, if anything other than
3705 ** IN_INDEX_NOOP is returned, the table opened with cursor iTab
3706 ** contains the values that make up the RHS. If IN_INDEX_NOOP is returned,
3707 ** the RHS has not yet been coded. */
3718 );
3719 #ifdef SQLITE_DEBUG
3720 /* Confirm that aiMap[] contains nVector integer values between 0 and
3721 ** nVector-1. */
3726 }
3727 #endif
3729 /* Code the LHS, the <expr> from "<expr> IN (...)". If the LHS is a
3730 ** vector, then it is stored in an array of nVector registers starting
3731 ** at r1.
3732 **
3733 ** sqlite3FindInIndex() might have reordered the fields of the LHS vector
3734 ** so that the fields are in the same order as an existing index. The
3735 ** aiMap[] array contains a mapping from the original LHS field order to
3736 ** the field order that matches the RHS index.
3737 **
3738 ** Avoid factoring the LHS of the IN(...) expression out of the loop,
3739 ** even if it is constant, as OP_Affinity may be used on the register
3740 ** by code generated below. */
3747 /* LHS fields are not reordered */
3750 /* Need to reorder the LHS fields according to aiMap */
3754 }
3755 }
3757 /* If sqlite3FindInIndex() did not find or create an index that is
3758 ** suitable for evaluating the IN operator, then evaluate using a
3759 ** sequence of comparisons.
3760 **
3761 ** This is step (1) in the in-operator.md optimized algorithm.
3762 */
3776 }
3781 }
3800 }
3801 }
3805 }
3809 }
3811 /* Step 2: Check to see if the LHS contains any NULL columns. If the
3812 ** LHS does contain NULLs then the result must be either FALSE or NULL.
3813 ** We will then skip the binary search of the RHS.
3814 */
3819 }
3826 }
3827 }
3829 /* Step 3. The LHS is now known to be non-NULL. Do the binary search
3830 ** of the RHS using the LHS as a probe. If found, the result is
3831 ** true.
3832 */
3834 /* In this case, the RHS is the ROWID of table b-tree and so we also
3835 ** know that the RHS is non-NULL. Hence, we combine steps 3 and 4
3836 ** into a single opcode. */
3843 /* Combine Step 3 and Step 5 into a single opcode */
3847 }
3848 /* Ordinary Step 3, for the case where FALSE and NULL are distinct */
3851 }
3853 /* Step 4. If the RHS is known to be non-NULL and we did not find
3854 ** an match on the search above, then the result must be FALSE.
3855 */
3859 }
3861 /* Step 5. If we do not care about the difference between NULL and
3862 ** FALSE, then just return false.
3863 */
3866 /* Step 6: Loop through rows of the RHS. Compare each row to the LHS.
3867 ** If any comparison is NULL, then the result is NULL. If all
3868 ** comparisons are FALSE then the final result is FALSE.
3869 **
3870 ** For a scalar LHS, it is sufficient to check just the first row
3871 ** of the RHS.
3872 */
3879 /* For nVector==1, combine steps 6 and 7 by immediately returning
3880 ** FALSE if the first comparison is not NULL */
3882 }
3894 }
3901 /* Step 7: If we reach this point, we know that the result must
3902 ** be false. */
3904 }
3906 /* Jumps here in order to return true. */
3909 sqlite3ExprCodeIN_finished:
3912 sqlite3ExprCodeIN_oom_error:
3915 }
3918 #ifndef SQLITE_OMIT_FLOATING_POINT
3919 /*
3920 ** Generate an instruction that will put the floating point
3921 ** value described by z[0..n-1] into register iMem.
3922 **
3923 ** The z[] string will probably not be zero-terminated. But the
3924 ** z[n] character is guaranteed to be something that does not look
3925 ** like the continuation of the number.
3926 */
3934 }
3935 }
3936 #endif
3939 /*
3940 ** Generate an instruction that will put the integer describe by
3941 ** text z[0..n-1] into register iMem.
3942 **
3943 ** Expr.u.zToken is always UTF8 and zero-terminated.
3944 */
3954 i64 value;
3959 #ifdef SQLITE_OMIT_FLOATING_POINT
3961 #else
3962 #ifndef SQLITE_OMIT_HEX_INTEGER
3967 #endif
3968 {
3970 }
3971 #endif
3975 }
3976 }
3977 }
3980 /* Generate code that will load into register regOut a value that is
3981 ** appropriate for the iIdxCol-th column of index pIdx.
3982 */
3989 ){
4000 }
4001 }
4003 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
4004 /*
4005 ** Generate code that will compute the value of generated column pCol
4006 ** and store the result in register regOut
4007 */
4013 ){
4023 }
4027 }
4030 }
4033 /*
4034 ** Generate code to extract the value of the iCol-th column of a table.
4035 */
4042 ){
4056 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
4069 }
4071 #endif
4080 }
4083 }
4084 }
4086 /*
4087 ** Generate code that will extract the iColumn-th column from
4088 ** table pTab and store the column value in register iReg.
4089 **
4090 ** There must be an open cursor to pTab in iTable when this routine
4091 ** is called. If iColumn<0 then code is generated that extracts the rowid.
4092 */
4099 u8 p5 /* P5 value for OP_Column + FLAGS */
4100 ){
4109 }
4111 }
4113 /*
4114 ** Generate code to move content from registers iFrom...iFrom+nReg-1
4115 ** over to iTo..iTo+nReg-1.
4116 */
4119 }
4121 /*
4122 ** Convert a scalar expression node to a TK_REGISTER referencing
4123 ** register iReg. The caller must ensure that iReg already contains
4124 ** the correct value for the expression.
4125 */
4133 }
4135 /*
4136 ** Evaluate an expression (either a vector or a scalar expression) and store
4137 ** the result in contiguous temporary registers. Return the index of
4138 ** the first register used to store the result.
4139 **
4140 ** If the returned result register is a temporary scalar, then also write
4141 ** that register number into *piFreeable. If the returned result register
4142 ** is not a temporary or if the expression is a vector set *piFreeable
4143 ** to 0.
4144 */
4153 #if SQLITE_OMIT_SUBQUERY
4155 #else
4157 #endif
4165 }
4166 }
4167 }
4169 }
4171 /*
4172 ** If the last opcode is a OP_Copy, then set the do-not-merge flag (p5)
4173 ** so that a subsequent copy will not be merged into this one.
4174 */
4178 }
4179 }
4181 /*
4182 ** Generate code to implement special SQL functions that are implemented
4183 ** in-line rather than by using the usual callbacks.
4184 */
4190 ){
4199 /* Attempt a direct implementation of the built-in COALESCE() and
4200 ** IFNULL() functions. This avoids unnecessary evaluation of
4201 ** arguments past the first non-NULL argument.
4202 */
4211 }
4215 }
4217 Expr caseExpr;
4222 }
4223 #ifdef SQLITE_ENABLE_OFFSET_SQL_FUNC
4230 }
4232 }
4233 #endif
4235 /* The UNLIKELY() function is a no-op. The result is the value
4236 ** of the first argument.
4237 */
4241 }
4243 /***********************************************************************
4244 ** Test-only SQL functions that are only usable if enabled
4245 ** via SQLITE_TESTCTRL_INTERNAL_FUNCTIONS
4246 */
4247 #if !defined(SQLITE_UNTESTABLE)
4249 /* Compare two expressions using sqlite3ExprCompare() */
4253 target);
4255 }
4258 /* Compare two expressions using sqlite3ExprImpliesExpr() */
4262 target);
4264 }
4267 /* Result of sqlite3ExprImpliesNonNullRow() */
4274 target);
4277 }
4279 }
4282 /* The AFFINITY() function evaluates to a string that describes
4283 ** the type affinity of the argument. This is used for testing of
4284 ** the SQLite type logic.
4285 */
4296 }
4298 }
4300 }
4302 /*
4303 ** Check to see if pExpr is one of the indexed expressions on pParse->pIdxEpr.
4304 ** If it is, then resolve the expression by reading from the index and
4305 ** return the register into which the value has been read. If pExpr is
4306 ** not an indexed expression, then return negative.
4307 */
4312 ){
4316 u8 exprAff;
4322 }
4329 ){
4330 /* Affinity mismatch on a generated column */
4332 }
4337 /* If the index is on a NULL row due to an outer join, then we
4338 ** cannot extract the value from the index. The value must be
4339 ** computed using the original expression. */
4354 }
4356 }
4358 }
4361 /*
4362 ** Expresion pExpr is guaranteed to be a TK_COLUMN or equivalent. This
4363 ** function checks the Parse.pIdxPartExpr list to see if this column
4364 ** can be replaced with a constant value. If so, it generates code to
4365 ** put the constant value in a register (ideally, but not necessarily,
4366 ** register iTarget) and returns the register number.
4367 **
4368 ** Or, if the TK_COLUMN cannot be replaced by a constant, zero is
4369 ** returned.
4370 */
4381 }
4388 }
4390 }
4391 }
4393 }
4396 /*
4397 ** Generate code into the current Vdbe to evaluate the given
4398 ** expression. Attempt to store the results in register "target".
4399 ** Return the register where results are stored.
4400 **
4401 ** With this routine, there is no guarantee that results will
4402 ** be stored in target. The result might be stored in some other
4403 ** register if it is convenient to do so. The calling function
4404 ** must check the return code and move the results to the desired
4405 ** register.
4406 */
4420 expr_code_doover:
4426 ){
4431 }
4440 /* Happens when the left table of a RIGHT JOIN is null and
4441 ** is using an expression index */
4443 #ifdef SQLITE_VDBE_COVERAGE
4444 /* Verify that the OP_Null above is exercised by tests
4445 ** tag-20230325-2 */
4448 #endif
4450 }
4459 /* No comment added */
4467 }
4468 }
4471 /* This case happens when the argument to an aggregate function
4472 ** is rewritten by aggregateConvertIndexedExprRefToColumn() */
4475 }
4476 /* Otherwise, fall thru into the TK_COLUMN case */
4477 /* no break */ deliberate_fall_through
4478 }
4483 /* This COLUMN expression is really a constant due to WHERE clause
4484 ** constraints, and that constant is coded by the pExpr->pLeft
4485 ** expression. However, make sure the constant has the correct
4486 ** datatype by applying the Affinity of the table column to the
4487 ** constant.
4488 */
4500 }
4502 }
4505 /* Other columns in the same row for CHECK constraints or
4506 ** generated columns or for inserting into partial index.
4507 ** The row is unpacked into registers beginning at
4508 ** 0-(pParse->iSelfTab). The rowid (if any) is in a register
4509 ** immediately prior to the first column.
4510 */
4522 }
4526 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
4532 }
4536 }
4547 }
4549 /* Coding an expression that is part of an index where column names
4550 ** in the index refer to the table to which the index belongs */
4552 }
4553 }
4556 ){
4558 }
4565 }
4569 }
4573 }
4574 #ifndef SQLITE_OMIT_FLOATING_POINT
4579 }
4580 #endif
4585 }
4587 /* Make NULL the default case so that if a bug causes an illegal
4588 ** Expr node to be passed into this function, it will be handled
4589 ** sanely and not crash. But keep the assert() to bring the problem
4590 ** to the attention of the developers. */
4594 }
4595 #ifndef SQLITE_OMIT_BLOB_LITERAL
4609 }
4610 #endif
4621 }
4623 }
4626 }
4627 #ifndef SQLITE_OMIT_CAST
4629 /* Expressions of the form: CAST(pLeft AS token) */
4636 }
4642 /* fall-through */
4669 }
4672 }
4674 }
4704 }
4711 #ifndef SQLITE_OMIT_FLOATING_POINT
4716 #endif
4726 }
4728 }
4737 }
4749 }
4764 }
4770 ){
4775 }
4777 }
4789 #ifndef SQLITE_OMIT_WINDOWFUNC
4792 }
4793 #endif
4796 /* SQL functions can be expensive. So try to avoid running them
4797 ** multiple times if we know they always give the same result */
4799 }
4807 #ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
4810 }
4811 #endif
4815 }
4823 }
4829 }
4832 }
4833 }
4840 }
4842 /* For length() and typeof() and octet_length() functions,
4843 ** set the P5 parameter to the OP_Column opcode to OPFLAG_LENGTHARG
4844 ** or OPFLAG_TYPEOFARG or OPFLAG_BYTELENARG respectively, to avoid
4845 ** unnecessary data loading.
4846 */
4848 u8 exprOp;
4861 }
4862 }
4867 }
4868 #ifndef SQLITE_OMIT_VIRTUALTABLE
4869 /* Possibly overload the function if the first argument is
4870 ** a virtual table column.
4871 **
4872 ** For infix functions (LIKE, GLOB, REGEXP, and MATCH) use the
4873 ** second argument, not the first, as the argument to test to
4874 ** see if it is a column in a virtual table. This is done because
4875 ** the left operand of infix functions (the operand we want to
4876 ** control overloading) ends up as the second argument to the
4877 ** function. The expression "A glob B" is equivalent to
4878 ** "glob(B,A). We want to use the A in "A glob B" to test
4879 ** for function overloading. But we use the B term in "glob(B,A)".
4880 */
4885 }
4886 #endif
4890 }
4898 }
4899 }
4901 }
4902 #ifndef SQLITE_OMIT_SUBQUERY
4913 ){
4917 }
4919 }
4926 }
4932 }
4934 }
4945 }
4949 /*
4950 ** x BETWEEN y AND z
4951 **
4952 ** This is equivalent to
4953 **
4954 ** x>=y AND x<=z
4955 **
4956 ** X is stored in pExpr->pLeft.
4957 ** Y is stored in pExpr->pList->a[0].pExpr.
4958 ** Z is stored in pExpr->pList->a[1].pExpr.
4959 */
4963 }
4966 /* A TK_COLLATE Expr node without the EP_Collate tag is a so-called
4967 ** "SOFT-COLLATE" that is added to constraints that are pushed down
4968 ** from outer queries into sub-queries by the push-down optimization.
4969 ** Clear subtypes as subtypes may not cross a subquery boundary.
4970 */
4978 }
4979 }
4984 }
4987 /* If the opcode is TK_TRIGGER, then the expression is a reference
4988 ** to a column in the new.* or old.* pseudo-tables available to
4989 ** trigger programs. In this case Expr.iTable is set to 1 for the
4990 ** new.* pseudo-table, or 0 for the old.* pseudo-table. Expr.iColumn
4991 ** is set to the column of the pseudo-table to read, or to -1 to
4992 ** read the rowid field.
4993 **
4994 ** The expression is implemented using an OP_Param opcode. The p1
4995 ** parameter is set to 0 for an old.rowid reference, or to (i+1)
4996 ** to reference another column of the old.* pseudo-table, where
4997 ** i is the index of the column. For a new.rowid reference, p1 is
4998 ** set to (n+1), where n is the number of columns in each pseudo-table.
4999 ** For a reference to any other column in the new.* pseudo-table, p1
5000 ** is set to (n+2+i), where n and i are as defined previously. For
5001 ** example, if the table on which triggers are being fired is
5002 ** declared as:
5003 **
5004 ** CREATE TABLE t1(a, b);
5005 **
5006 ** Then p1 is interpreted as follows:
5007 **
5008 ** p1==0 -> old.rowid p1==3 -> new.rowid
5009 ** p1==1 -> old.a p1==4 -> new.a
5010 ** p1==2 -> old.b p1==5 -> new.b
5011 */
5031 ));
5033 #ifndef SQLITE_OMIT_FLOATING_POINT
5034 /* If the column has REAL affinity, it may currently be stored as an
5035 ** integer. Use OP_RealAffinity to make sure it is really real.
5036 **
5037 ** EVIDENCE-OF: R-60985-57662 SQLite will convert the value back to
5038 ** floating point when extracting it from the record. */
5041 }
5042 #endif
5044 }
5049 }
5051 /* TK_IF_NULL_ROW Expr nodes are inserted ahead of expressions
5052 ** that derive from the right-hand table of a LEFT JOIN. The
5053 ** Expr.iTable value is the table number for the right-hand table.
5054 ** The expression is only evaluated if that table is not currently
5055 ** on a LEFT JOIN NULL row.
5056 */
5066 }
5070 target);
5073 }
5074 }
5076 /* The OP_IfNullRow opcode above can overwrite the result register with
5077 ** NULL. So we have to ensure that the result register is not a value
5078 ** that is suppose to be a constant. Two defenses are needed:
5079 ** (1) Temporarily disable factoring of constant expressions
5080 ** (2) Make sure the computed value really is stored in register
5081 ** "target" and not someplace else.
5082 */
5089 }
5091 /*
5092 ** Form A:
5093 ** CASE x WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
5094 **
5095 ** Form B:
5096 ** CASE WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
5097 **
5098 ** Form A is can be transformed into the equivalent form B as follows:
5099 ** CASE WHEN x=e1 THEN r1 WHEN x=e2 THEN r2 ...
5100 ** WHEN x=eN THEN rN ELSE y END
5101 **
5102 ** X (if it exists) is in pExpr->pLeft.
5103 ** Y is in the last element of pExpr->x.pList if pExpr->x.pList->nExpr is
5104 ** odd. The Y is also optional. If the number of elements in x.pList
5105 ** is even, then Y is omitted and the "otherwise" result is NULL.
5106 ** Ei is in pExpr->pList->a[i*2] and Ri is pExpr->pList->a[i*2+1].
5107 **
5108 ** The result of the expression is the Ri for the first matching Ei,
5109 ** or if there is no matching Ei, the ELSE term Y, or if there is
5110 ** no ELSE term, NULL.
5111 */
5136 }
5144 /* Ticket b351d95f9cd5ef17e9d9dbae18f5ca8611190001:
5145 ** The value in regFree1 might get SCopy-ed into the file result.
5146 ** So make sure that the regFree1 register is not reused for other
5147 ** purposes and possibly overwritten. */
5149 }
5156 }
5164 }
5169 }
5174 }
5175 #ifndef SQLITE_OMIT_TRIGGER
5181 );
5186 }
5189 }
5199 }
5202 }
5203 #endif
5204 }
5208 }
5210 /*
5211 ** Generate code that will evaluate expression pExpr just one time
5212 ** per prepared statement execution.
5213 **
5214 ** If the expression uses functions (that might throw an exception) then
5215 ** guard them with an OP_Once opcode to ensure that the code is only executed
5216 ** once. If no functions are involved, then factor the code out and put it at
5217 ** the end of the prepared statement in the initialization section.
5218 **
5219 ** If regDest>0 then the result is always stored in that register and the
5220 ** result is not reusable. If regDest<0 then this routine is free to
5221 ** store the value wherever it wants. The register where the expression
5222 ** is stored is returned. When regDest<0, two identical expressions might
5223 ** code to the same register, if they do not contain function calls and hence
5224 ** are factored out into the initialization section at the end of the
5225 ** prepared statement.
5226 */
5231 ){
5242 ){
5244 }
5245 }
5246 }
5257 }
5268 }
5270 }
5272 }
5274 /*
5275 ** Generate code to evaluate an expression and store the results
5276 ** into a register. Return the register number where the results
5277 ** are stored.
5278 **
5279 ** If the register is a temporary register that can be deallocated,
5280 ** then write its number into *pReg. If the result register is not
5281 ** a temporary, then set *pReg to zero.
5282 **
5283 ** If pExpr is a constant, then this routine might generate this
5284 ** code to fill the register in the initialization section of the
5285 ** VDBE program, in order to factor it out of the evaluation loop.
5286 */
5294 ){
5305 }
5306 }
5308 }
5310 /*
5311 ** Generate code that will evaluate expression pExpr and store the
5312 ** results in register target. The results are guaranteed to appear
5313 ** in register target.
5314 */
5324 u8 op;
5327 ){
5331 }
5333 }
5334 }
5336 /*
5337 ** Make a transient copy of expression pExpr and then code it using
5338 ** sqlite3ExprCode(). This routine works just like sqlite3ExprCode()
5339 ** except that the input expression is guaranteed to be unchanged.
5340 */
5346 }
5348 /*
5349 ** Generate code that will evaluate expression pExpr and store the
5350 ** results in register target. The results are guaranteed to appear
5351 ** in register target. If the expression is constant, then this routine
5352 ** might choose to code the expression at initialization time.
5353 */
5359 }
5360 }
5362 /*
5363 ** Generate code that pushes the value of every element of the given
5364 ** expression list into a sequence of registers beginning at target.
5365 **
5366 ** Return the number of elements evaluated. The number returned will
5367 ** usually be pList->nExpr but might be reduced if SQLITE_ECEL_OMITREF
5368 ** is defined.
5369 **
5370 ** The SQLITE_ECEL_DUP flag prevents the arguments from being
5371 ** filled using OP_SCopy. OP_Copy must be used instead.
5372 **
5373 ** The SQLITE_ECEL_FACTOR argument allows constant arguments to be
5374 ** factored out into initialization code.
5375 **
5376 ** The SQLITE_ECEL_REF flag means that expressions in the list with
5377 ** ExprList.a[].u.x.iOrderByCol>0 have already been evaluated and stored
5378 ** in registers at srcReg, and so the value can be copied from there.
5379 ** If SQLITE_ECEL_OMITREF is also set, then the values with u.x.iOrderByCol>0
5380 ** are simply omitted rather than being copied from srcReg.
5381 */
5387 u8 flags /* SQLITE_ECEL_* flags */
5388 ){
5400 #ifdef SQLITE_ENABLE_SORTER_REFERENCES
5402 i--;
5403 n--;
5405 #endif
5408 i--;
5409 n--;
5412 }
5415 ){
5426 ){
5430 }
5431 }
5432 }
5433 }
5435 }
5437 /*
5438 ** Generate code for a BETWEEN operator.
5439 **
5440 ** x BETWEEN y AND z
5441 **
5442 ** The above is equivalent to
5443 **
5444 ** x>=y AND x<=z
5445 **
5446 ** Code it as such, taking care to do the common subexpression
5447 ** elimination of x.
5448 **
5449 ** The xJumpIf parameter determines details:
5450 **
5451 ** NULL: Store the boolean result in reg[dest]
5452 ** sqlite3ExprIfTrue: Jump to dest if true
5453 ** sqlite3ExprIfFalse: Jump to dest if false
5454 **
5455 ** The jumpIfNull parameter is ignored if xJumpIf is NULL.
5456 */
5463 ){
5491 /* Mark the expression is being from the ON or USING clause of a join
5492 ** so that the sqlite3ExprCodeTarget() routine will not attempt to move
5493 ** it into the Parse.pConstExpr list. We should use a new bit for this,
5494 ** for clarity, but we are out of bits in the Expr.flags field so we
5495 ** have to reuse the EP_OuterON bit. Bummer. */
5498 }
5500 }
5503 /* Ensure adequate test coverage */
5513 }
5515 /*
5516 ** Generate code for a boolean expression such that a jump is made
5517 ** to the label "dest" if the expression is true but execution
5518 ** continues straight thru if the expression is false.
5519 **
5520 ** If the expression evaluates to NULL (neither true nor false), then
5521 ** take the jump if the jumpIfNull flag is SQLITE_JUMPIFNULL.
5522 **
5523 ** This code depends on the fact that certain token values (ex: TK_EQ)
5524 ** are the same as opcode values (ex: OP_Eq) that implement the corresponding
5525 ** operation. Special comments in vdbe.c and the mkopcodeh.awk script in
5526 ** the make process cause these values to align. Assert()s in the code
5527 ** below verify that the numbers are aligned correctly.
5528 */
5558 }
5560 }
5565 }
5580 }
5582 }
5589 /* no break */ deliberate_fall_through
5615 }
5627 }
5632 }
5633 #ifndef SQLITE_OMIT_SUBQUERY
5641 }
5642 #endif
5644 default_expr:
5648 /* No-op */
5655 }
5657 }
5658 }
5661 }
5663 /*
5664 ** Generate code for a boolean expression such that a jump is made
5665 ** to the label "dest" if the expression is false but execution
5666 ** continues straight thru if the expression is true.
5667 **
5668 ** If the expression evaluates to NULL (neither true nor false) then
5669 ** jump if jumpIfNull is SQLITE_JUMPIFNULL or fall through if jumpIfNull
5670 ** is 0.
5671 */
5684 /* The value of pExpr->op and op are related as follows:
5685 **
5686 ** pExpr->op op
5687 ** --------- ----------
5688 ** TK_ISNULL OP_NotNull
5689 ** TK_NOTNULL OP_IsNull
5690 ** TK_NE OP_Eq
5691 ** TK_EQ OP_Ne
5692 ** TK_GT OP_Le
5693 ** TK_LE OP_Gt
5694 ** TK_GE OP_Lt
5695 ** TK_LT OP_Ge
5696 **
5697 ** For other values of pExpr->op, op is undefined and unused.
5698 ** The value of TK_ and OP_ constants are arranged such that we
5699 ** can compute the mapping above using the following expression.
5700 ** Assert()s verify that the computation is correct.
5701 */
5704 /* Verify correct alignment of TK_ and OP_ constants
5705 */
5732 }
5734 }
5739 }
5749 /* IS TRUE and IS NOT FALSE */
5754 /* IS FALSE and IS NOT TRUE */
5757 }
5759 }
5766 /* no break */ deliberate_fall_through
5792 }
5802 }
5807 }
5808 #ifndef SQLITE_OMIT_SUBQUERY
5816 }
5818 }
5819 #endif
5821 default_expr:
5825 /* no-op */
5832 }
5834 }
5835 }
5838 }
5840 /*
5841 ** Like sqlite3ExprIfFalse() except that a copy is made of pExpr before
5842 ** code generation, and that copy is deleted after code generation. This
5843 ** ensures that the original pExpr is unchanged.
5844 */
5850 }
5852 }
5854 /*
5855 ** Expression pVar is guaranteed to be an SQL variable. pExpr may be any
5856 ** type of expression.
5857 **
5858 ** If pExpr is a simple SQL value - an integer, real, string, blob
5859 ** or NULL value - then the VDBE currently being prepared is configured
5860 ** to re-prepare each time a new value is bound to variable pVar.
5861 **
5862 ** Additionally, if pExpr is a simple SQL value and the value is the
5863 ** same as that currently bound to variable pVar, non-zero is returned.
5864 ** Otherwise, if the values are not the same or if pExpr is not a simple
5865 ** SQL value, zero is returned.
5866 */
5871 ){
5884 }
5886 }
5889 }
5892 }
5894 /*
5895 ** Do a deep comparison of two expression trees. Return 0 if the two
5896 ** expressions are completely identical. Return 1 if they differ only
5897 ** by a COLLATE operator at the top level. Return 2 if there are differences
5898 ** other than the top-level COLLATE operator.
5899 **
5900 ** If any subelement of pB has Expr.iTable==(-1) then it is allowed
5901 ** to compare equal to an equivalent element in pA with Expr.iTable==iTab.
5902 **
5903 ** The pA side might be using TK_REGISTER. If that is the case and pB is
5904 ** not using TK_REGISTER but is otherwise equivalent, then still return 0.
5905 **
5906 ** Sometimes this routine will return 2 even if the two expressions
5907 ** really are equivalent. If we cannot prove that the expressions are
5908 ** identical, we return 2 just to be safe. So if this routine
5909 ** returns 2, then you do not really know for certain if the two
5910 ** expressions are the same. But if you get a 0 or 1 return, then you
5911 ** can be sure the expressions are the same. In the places where
5912 ** this routine is used, it does not hurt to get an extra 2 - that
5913 ** just might result in some slightly slower code. But returning
5914 ** an incorrect 0 or 1 could lead to a malfunction.
5915 **
5916 ** If pParse is not NULL then TK_VARIABLE terms in pA with bindings in
5917 ** pParse->pReprepare can be matched against literals in pB. The
5918 ** pParse->pVdbe->expmask bitmask is updated for each variable referenced.
5919 ** If pParse is NULL (the normal case) then any TK_VARIABLE term in
5920 ** Argument pParse should normally be NULL. If it is not NULL and pA or
5921 ** pB causes a return value of 2.
5922 */
5927 int iTab
5928 ){
5929 u32 combinedFlags;
5932 }
5935 }
5940 }
5942 }
5946 }
5949 }
5952 ){
5953 /* fall through */
5956 }
5957 }
5963 #ifndef SQLITE_OMIT_WINDOWFUNC
5967 }
5971 }
5972 }
5973 #endif
5983 ){
5985 }
5986 }
5998 ){
6003 }
6004 }
6005 }
6007 }
6009 /*
6010 ** Compare two ExprList objects. Return 0 if they are identical, 1
6011 ** if they are certainly different, or 2 if it is not possible to
6012 ** determine if they are identical or not.
6013 **
6014 ** If any subelement of pB has Expr.iTable==(-1) then it is allowed
6015 ** to compare equal to an equivalent element in pA with Expr.iTable==iTab.
6016 **
6017 ** This routine might return non-zero for equivalent ExprLists. The
6018 ** only consequence will be disabled optimizations. But this routine
6019 ** must never return 0 if the two ExprList objects are different, or
6020 ** a malfunction will result.
6021 **
6022 ** Two NULL pointers are considered to be the same. But a NULL pointer
6023 ** always differs from a non-NULL pointer.
6024 */
6036 }
6038 }
6040 /*
6041 ** Like sqlite3ExprCompare() except COLLATE operators at the top-level
6042 ** are ignored.
6043 */
6048 iTab);
6049 }
6051 /*
6052 ** Return non-zero if Expr p can only be true if pNN is not NULL.
6053 **
6054 ** Or if seenNot is true, return non-zero if Expr p can only be
6055 ** non-NULL if pNN is not NULL
6056 */
6063 ){
6068 }
6074 }
6084 ){
6086 }
6088 }
6102 /* no break */ deliberate_fall_through
6108 /* no break */ deliberate_fall_through
6109 }
6115 }
6120 }
6124 }
6125 }
6127 }
6129 /*
6130 ** Return true if we can prove the pE2 will always be true if pE1 is
6131 ** true. Return false if we cannot complete the proof or if pE2 might
6132 ** be false. Examples:
6133 **
6134 ** pE1: x==5 pE2: x==5 Result: true
6135 ** pE1: x>0 pE2: x==5 Result: false
6136 ** pE1: x=21 pE2: x=21 OR y=43 Result: true
6137 ** pE1: x!=123 pE2: x IS NOT NULL Result: true
6138 ** pE1: x!=?1 pE2: x IS NOT NULL Result: true
6139 ** pE1: x IS NULL pE2: x IS NOT NULL Result: false
6140 ** pE1: x IS ?2 pE2: x IS NOT NULL Result: false
6141 **
6142 ** When comparing TK_COLUMN nodes between pE1 and pE2, if pE2 has
6143 ** Expr.iTable<0 then assume a table number given by iTab.
6144 **
6145 ** If pParse is not NULL, then the values of bound variables in pE1 are
6146 ** compared against literal values in pE2 and pParse->pVdbe->expmask is
6147 ** modified to record which bound variables are referenced. If pParse
6148 ** is NULL, then false will be returned if pE1 contains any bound variables.
6149 **
6150 ** When in doubt, return false. Returning true might give a performance
6151 ** improvement. Returning false might cause a performance reduction, but
6152 ** it will always give the correct answer and is hence always safe.
6153 */
6158 int iTab
6159 ){
6162 }
6166 ){
6168 }
6171 ){
6173 }
6175 }
6177 /* This is a helper function to impliesNotNullRow(). In this routine,
6178 ** set pWalker->eCode to one only if *both* of the input expressions
6179 ** separately have the implies-not-null-row property.
6180 */
6187 }
6188 }
6189 }
6191 /*
6192 ** This is the Expr node callback for sqlite3ExprImpliesNonNullRow().
6193 ** If the expression node requires that the table at pWalker->iCur
6194 ** have one or more non-NULL column, then set pWalker->eCode to 1 and abort.
6195 **
6196 ** pWalker->mWFlags is non-zero if this inquiry is being undertaking on
6197 ** behalf of a RIGHT JOIN (or FULL JOIN). That makes a difference when
6198 ** evaluating terms in the ON clause of an inner join.
6199 **
6200 ** This routine controls an optimization. False positives (setting
6201 ** pWalker->eCode to 1 when it should not be) are deadly, but false-negatives
6202 ** (never setting pWalker->eCode) is a harmless missed optimization.
6203 */
6209 /* If iCur is used in an inner-join ON clause to the left of a
6210 ** RIGHT JOIN, that does *not* mean that the table must be non-null.
6211 ** But it is difficult to check for that condition precisely.
6212 ** To keep things simple, any use of iCur from any inner-join is
6213 ** ignored while attempting to simplify a RIGHT JOIN. */
6215 }
6239 }
6244 /* Both sides of an AND or OR must separately imply non-null-row.
6245 ** Consider these cases:
6246 ** 1. NOT (x AND y)
6247 ** 2. x OR y
6248 ** If only one of x or y is non-null-row, then the overall expression
6249 ** can be true if the other arm is false (case 1) or true (case 2).
6250 */
6257 /* Beware of "x NOT IN ()" and "x NOT IN (SELECT 1 WHERE false)",
6258 ** both of which can be true. But apart from these cases, if
6259 ** the left-hand side of the IN is NULL then the IN itself will be
6260 ** NULL. */
6263 }
6267 /* In "x NOT BETWEEN y AND z" either x must be non-null-row or else
6268 ** both y and z must be non-null row */
6276 /* Virtual tables are allowed to use constraints like x=NULL. So
6277 ** a term of the form x=y does not prove that y is not null if x
6278 ** is the column of a virtual table */
6293 /* The y.pTab=0 assignment in wherecode.c always happens after the
6294 ** impliesNotNullRow() test */
6303 ){
6305 }
6306 /* no break */ deliberate_fall_through
6307 }
6310 }
6311 }
6313 /*
6314 ** Return true (non-zero) if expression p can only be true if at least
6315 ** one column of table iTab is non-null. In other words, return true
6316 ** if expression p will always be NULL or false if every column of iTab
6317 ** is NULL.
6318 **
6319 ** False negatives are acceptable. In other words, it is ok to return
6320 ** zero even if expression p will never be true of every column of iTab
6321 ** is NULL. A false negative is merely a missed optimization opportunity.
6322 **
6323 ** False positives are not allowed, however. A false positive may result
6324 ** in an incorrect answer.
6325 **
6326 ** Terms of p that are marked with EP_OuterON (and hence that come from
6327 ** the ON or USING clauses of OUTER JOINS) are excluded from the analysis.
6328 **
6329 ** This routine is used to check if a LEFT JOIN can be converted into
6330 ** an ordinary JOIN. The p argument is the WHERE clause. If the WHERE
6331 ** clause requires that some column of the right table of the LEFT JOIN
6332 ** be non-NULL, then the LEFT JOIN can be safely converted into an
6333 ** ordinary join.
6334 */
6336 Walker w;
6345 }
6346 }
6355 }
6357 /*
6358 ** An instance of the following structure is used by the tree walker
6359 ** to determine if an expression can be evaluated by reference to the
6360 ** index only, without having to do a search for the corresponding
6361 ** table entry. The IdxCover.pIdx field is the index. IdxCover.iCur
6362 ** is the cursor for the table.
6363 */
6367 };
6369 /*
6370 ** Check to see if there are references to columns in table
6371 ** pWalker->u.pIdxCover->iCur can be satisfied using the index
6372 ** pWalker->u.pIdxCover->pIdx.
6373 */
6378 ){
6381 }
6383 }
6385 /*
6386 ** Determine if an index pIdx on table with cursor iCur contains will
6387 ** the expression pExpr. Return true if the index does cover the
6388 ** expression and false if the pExpr expression references table columns
6389 ** that are not found in the index pIdx.
6390 **
6391 ** An index covering an expression means that the expression can be
6392 ** evaluated using only the index and without having to lookup the
6393 ** corresponding table entry.
6394 */
6399 ){
6400 Walker w;
6409 }
6412 /* Structure used to pass information throughout the Walker in order to
6413 ** implement sqlite3ReferencesSrcList().
6414 */
6420 };
6422 /*
6423 ** Walker SELECT callbacks for sqlite3ReferencesSrcList().
6424 **
6425 ** When entering a new subquery on the pExpr argument, add all FROM clause
6426 ** entries for that subquery to the exclude list.
6427 **
6428 ** When leaving the subquery, remove those entries from the exclude list.
6429 */
6444 }
6447 }
6449 }
6456 }
6457 }
6459 /* This is the Walker EXPR callback for sqlite3ReferencesSrcList().
6460 **
6461 ** Set the 0x01 bit of pWalker->eCode if there is a reference to any
6462 ** of the tables shown in RefSrcList.pRef.
6463 **
6464 ** Set the 0x02 bit of pWalker->eCode if there is a reference to a
6465 ** table is in neither RefSrcList.pRef nor RefSrcList.aiExclude.
6466 */
6470 ){
6479 }
6480 }
6484 }
6485 }
6487 }
6489 /*
6490 ** Check to see if pExpr references any tables in pSrcList.
6491 ** Possible return values:
6492 **
6493 ** 1 pExpr does references a table in pSrcList.
6494 **
6495 ** 0 pExpr references some table that is not defined in either
6496 ** pSrcList or in subqueries of pExpr itself.
6497 **
6498 ** -1 pExpr only references no tables at all, or it only
6499 ** references tables defined in subqueries of pExpr itself.
6500 **
6501 ** As currently used, pExpr is always an aggregate function call. That
6502 ** fact is exploited for efficiency.
6503 */
6505 Walker w;
6524 }
6525 #ifndef SQLITE_OMIT_WINDOWFUNC
6528 }
6529 #endif
6537 }
6538 }
6540 /*
6541 ** This is a Walker expression node callback.
6542 **
6543 ** For Expr nodes that contain pAggInfo pointers, make sure the AggInfo
6544 ** object that is referenced does not refer directly to the Expr. If
6545 ** it does, make a copy. This is done because the pExpr argument is
6546 ** subject to change.
6547 **
6548 ** The copy is scheduled for deletion using the sqlite3ExprDeferredDelete()
6549 ** which builds on the sqlite3ParserAddCleanup() mechanism.
6550 */
6554 ){
6563 ){
6568 }
6569 }
6574 ){
6579 }
6580 }
6581 }
6582 }
6584 }
6586 /*
6587 ** Initialize a Walker object so that will persist AggInfo entries referenced
6588 ** by the tree that is walked.
6589 */
6595 }
6597 /*
6598 ** Add a new element to the pAggInfo->aCol[] array. Return the index of
6599 ** the new element. Return a negative number if malloc fails.
6600 */
6604 db,
6608 &i
6609 );
6611 }
6613 /*
6614 ** Add a new element to the pAggInfo->aFunc[] array. Return the index of
6615 ** the new element. Return a negative number if malloc fails.
6616 */
6620 db,
6624 &i
6625 );
6627 }
6629 /*
6630 ** Search the AggInfo object for an aCol[] entry that has iTable and iColumn.
6631 ** Return the index in aCol[] of the entry that describes that column.
6632 **
6633 ** If no prior entry is found, create a new one and return -1. The
6634 ** new column will have an index of pAggInfo->nColumn-1.
6635 */
6640 ){
6651 ){
6653 }
6654 }
6657 /* OOM on resize */
6660 }
6678 ){
6681 }
6682 }
6683 }
6686 }
6687 fix_up_expr:
6693 }
6695 }
6697 /*
6698 ** This is the xExprCallback for a tree walker. It is used to
6699 ** implement sqlite3ExprAnalyzeAggregates(). See sqlite3ExprAnalyzeAggregates
6700 ** for additional information.
6701 */
6714 Expr tmp;
6722 }
6727 }
6732 /* If we reach this point, it means that expression pExpr can be
6733 ** translated into a reference to an index column as described by
6734 ** pIEpr.
6735 */
6748 }
6755 /* Check to see if the column is in one of the tables in the FROM
6756 ** clause of the aggregate query */
6766 }
6768 }
6772 ){
6773 /* Check to see if pExpr is a duplicate of another aggregate
6774 ** function that is already in the pAggInfo structure
6775 */
6781 }
6782 }
6784 /* pExpr is original. Make a new entry in pAggInfo->aFunc[]
6785 */
6800 ){
6801 /* The NEEDCOLL test above causes any ORDER BY clause on
6802 ** aggregate min() or max() to be ignored. */
6815 ){
6820 }
6823 }
6828 }
6829 }
6830 }
6831 /* Make pExpr point to the appropriate pAggInfo->aFunc[] entry
6832 */
6840 }
6841 }
6842 }
6844 }
6846 /*
6847 ** Analyze the pExpr expression looking for aggregate functions and
6848 ** for variables that need to be added to AggInfo object that pNC->pAggInfo
6849 ** points to. Additional entries are made on the AggInfo object as
6850 ** necessary.
6851 **
6852 ** This routine should only be called after the expression has been
6853 ** analyzed by sqlite3ResolveExprNames().
6854 */
6856 Walker w;
6865 }
6867 /*
6868 ** Call sqlite3ExprAnalyzeAggregates() for every expression in an
6869 ** expression list. Return the number of errors.
6870 **
6871 ** If an error is found, the analysis is cut short.
6872 */
6879 }
6880 }
6881 }
6883 /*
6884 ** Allocate a single new register for use to hold some intermediate result.
6885 */
6889 }
6891 }
6893 /*
6894 ** Deallocate a register, making available for reuse for some other
6895 ** purpose.
6896 */
6902 }
6903 }
6904 }
6906 /*
6907 ** Allocate or deallocate a block of nReg consecutive registers.
6908 */
6920 }
6922 }
6927 }
6932 }
6933 }
6935 /*
6936 ** Mark all temporary registers as being unavailable for reuse.
6937 **
6938 ** Always invoke this procedure after coding a subroutine or co-routine
6939 ** that might be invoked from other parts of the code, to ensure that
6940 ** the sub/co-routine does not use registers in common with the code that
6941 ** invokes the sub/co-routine.
6942 */
6946 }
6948 /*
6949 ** Make sure sufficient registers have been allocated so that
6950 ** iReg is a valid register number.
6951 */
6954 }
6956 #if defined(SQLITE_ENABLE_STAT4) || defined(SQLITE_DEBUG)
6957 /*
6958 ** Return the latest reusable register in the set of all registers.
6959 ** The value returned is no less than iMin. If any register iMin or
6960 ** greater is in permanent use, then return one more than that last
6961 ** permanent register.
6962 */
6970 }
6971 }
6972 }
6976 }
6979 /*
6980 ** Validate that no temporary register falls within the range of
6981 ** iFirst..iLast, inclusive. This routine is only call from within assert()
6982 ** statements.
6983 */
6984 #ifdef SQLITE_DEBUG
6990 ){
6992 }
6996 }
6997 }
7004 }
7005 }
7007 }