| blob | 393cd528f1f90af8d562bb1629c1ef846c1087a5 |
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 C code routines that are called by the parser
13 ** to handle INSERT statements in SQLite.
14 */
17 /*
18 ** Generate code that will
19 **
20 ** (1) acquire a lock for table pTab then
21 ** (2) open pTab as cursor iCur.
22 **
23 ** If pTab is a WITHOUT ROWID table, then it is the PRIMARY KEY index
24 ** for that table that is actually opened.
25 */
32 ){
50 }
51 }
53 /*
54 ** Return a pointer to the column affinity string associated with index
55 ** pIdx. A column affinity string has one character for each column in
56 ** the table, according to the affinity of the column:
57 **
58 ** Character Column affinity
59 ** ------------------------------
60 ** 'A' BLOB
61 ** 'B' TEXT
62 ** 'C' NUMERIC
63 ** 'D' INTEGER
64 ** 'F' REAL
65 **
66 ** An extra 'D' is appended to the end of the string to cover the
67 ** rowid that appears as the last column in every index.
68 **
69 ** Memory for the buffer containing the column index affinity string
70 ** is managed along with the rest of the Index structure. It will be
71 ** released when sqlite3DeleteIndex() is called.
72 */
75 /* The first time a column affinity string for a particular index is
76 ** required, it is allocated and populated here. It is then stored as
77 ** a member of the Index structure for subsequent use.
78 **
79 ** The column affinity string will eventually be deleted by
80 ** sqliteDeleteIndex() when the Index structure itself is cleaned
81 ** up.
82 */
89 }
101 }
105 }
107 }
110 }
112 /*
113 ** Compute the affinity string for table pTab, if it has not already been
114 ** computed. As an optimization, omit trailing SQLITE_AFF_BLOB affinities.
115 **
116 ** If the affinity exists (if it is no entirely SQLITE_AFF_BLOB values) and
117 ** if iReg>0 then code an OP_Affinity opcode that will set the affinities
118 ** for register iReg and following. Or if affinities exists and iReg==0,
119 ** then just set the P4 operand of the previous opcode (which should be
120 ** an OP_MakeRecord) to the affinity string.
121 **
122 ** A column affinity string has one character per column:
123 **
124 ** Character Column affinity
125 ** ------------------------------
126 ** 'A' BLOB
127 ** 'B' TEXT
128 ** 'C' NUMERIC
129 ** 'D' INTEGER
130 ** 'E' REAL
131 */
141 }
147 }
148 }
153 }
161 }
162 }
163 }
165 /*
166 ** Return non-zero if the table pTab in database iDb or any of its indices
167 ** have been opened at any point in the VDBE program. This is used to see if
168 ** a statement of the form "INSERT INTO <iDb, pTab> SELECT ..." can
169 ** run without using a temporary table for the results of the SELECT.
170 */
175 #ifndef SQLITE_OMIT_VIRTUALTABLE
177 #endif
187 }
191 }
192 }
193 }
194 #ifndef SQLITE_OMIT_VIRTUALTABLE
199 }
200 #endif
201 }
203 }
205 /* This walker callback will compute the union of colFlags flags for all
206 ** referenced columns in a CHECK constraint or generated column expression.
207 */
212 }
214 }
216 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
217 /*
218 ** All regular columns for table pTab have been puts into registers
219 ** starting with iRegStore. The registers that correspond to STORED
220 ** or VIRTUAL columns have not yet been initialized. This routine goes
221 ** back and computes the values for those columns based on the previously
222 ** computed normal columns.
223 */
228 ){
230 Walker w;
239 /* Before computing generated columns, first go through and make sure
240 ** that appropriate affinity has been applied to the regular columns
241 */
245 ){
246 /* Change the OP_Affinity argument to '@' (NONE) for all stored
247 ** columns. '@' is the no-op affinity and those columns have not
248 ** yet been computed. */
256 }
259 }
260 jj++;
261 }
262 }
264 /* Because there can be multiple generated columns that refer to one another,
265 ** this is a two-pass algorithm. On the first pass, mark all generated
266 ** columns as "not available".
267 */
273 }
274 }
281 /* On the second pass, compute the value of each NOT-AVAILABLE column.
282 ** Companion code in the TK_COLUMN case of sqlite3ExprCodeTarget() will
283 ** compute dependencies and mark remove the COLSPAN_NOTAVAIL mark, as
284 ** they are needed.
285 */
301 }
307 }
308 }
312 }
314 }
318 #ifndef SQLITE_OMIT_AUTOINCREMENT
319 /*
320 ** Locate or create an AutoincInfo structure associated with table pTab
321 ** which is in database iDb. Return the register number for the register
322 ** that holds the maximum rowid. Return zero if pTab is not an AUTOINCREMENT
323 ** table. (Also return zero when doing a VACUUM since we do not want to
324 ** update the AUTOINCREMENT counters during a VACUUM.)
325 **
326 ** There is at most one AutoincInfo structure per table even if the
327 ** same table is autoincremented multiple times due to inserts within
328 ** triggers. A new AutoincInfo structure is created if this is the
329 ** first use of table pTab. On 2nd and subsequent uses, the original
330 ** AutoincInfo structure is used.
331 **
332 ** Four consecutive registers are allocated:
333 **
334 ** (1) The name of the pTab table.
335 ** (2) The maximum ROWID of pTab.
336 ** (3) The rowid in sqlite_sequence of pTab
337 ** (4) The original value of the max ROWID in pTab, or NULL if none
338 **
339 ** The 2nd register is the one that is returned. That is all the
340 ** insert routine needs to know about.
341 */
346 ){
351 ){
356 /* Verify that the sqlite_sequence table exists and is an ordinary
357 ** rowid table with exactly two columns.
358 ** Ticket d8dc2b3a58cd5dc2918a1d4acb 2018-05-23 */
363 ){
367 }
381 }
383 }
385 }
387 /*
388 ** This routine generates code that will initialize all of the
389 ** register used by the autoincrement tracker.
390 */
398 /* This routine is never called during trigger-generation. It is
399 ** only called from the top-level */
419 };
441 }
442 }
444 /*
445 ** Update the maximum rowid for an autoincrement calculation.
446 **
447 ** This routine should be called when the regRowid register holds a
448 ** new rowid that is about to be inserted. If that new rowid is
449 ** larger than the maximum rowid in the memId memory cell, then the
450 ** memory cell is updated.
451 */
455 }
456 }
458 /*
459 ** This routine generates the code needed to write autoincrement
460 ** maximum rowid values back into the sqlite_sequence register.
461 ** Every statement that might do an INSERT into an autoincrement
462 ** table (either directly or through triggers) needs to call this
463 ** routine just before the "exit" code.
464 */
479 };
500 }
501 }
504 }
505 #else
506 /*
507 ** If SQLITE_OMIT_AUTOINCREMENT is defined, then the three routines
508 ** above are all no-ops
509 */
510 # define autoIncBegin(A,B,C) (0)
511 # define autoIncStep(A,B,C)
515 /* Forward declaration */
522 );
524 /*
525 ** This routine is called to handle SQL of the following forms:
526 **
527 ** insert into TABLE (IDLIST) values(EXPRLIST),(EXPRLIST),...
528 ** insert into TABLE (IDLIST) select
529 ** insert into TABLE (IDLIST) default values
530 **
531 ** The IDLIST following the table name is always optional. If omitted,
532 ** then a list of all (non-hidden) columns for the table is substituted.
533 ** The IDLIST appears in the pColumn parameter. pColumn is NULL if IDLIST
534 ** is omitted.
535 **
536 ** For the pSelect parameter holds the values to be inserted for the
537 ** first two forms shown above. A VALUES clause is really just short-hand
538 ** for a SELECT statement that omits the FROM clause and everything else
539 ** that follows. If the pSelect parameter is NULL, that means that the
540 ** DEFAULT VALUES form of the INSERT statement is intended.
541 **
542 ** The code generated follows one of four templates. For a simple
543 ** insert with data coming from a single-row VALUES clause, the code executes
544 ** once straight down through. Pseudo-code follows (we call this
545 ** the "1st template"):
546 **
547 ** open write cursor to <table> and its indices
548 ** put VALUES clause expressions into registers
549 ** write the resulting record into <table>
550 ** cleanup
551 **
552 ** The three remaining templates assume the statement is of the form
553 **
554 ** INSERT INTO <table> SELECT ...
555 **
556 ** If the SELECT clause is of the restricted form "SELECT * FROM <table2>" -
557 ** in other words if the SELECT pulls all columns from a single table
558 ** and there is no WHERE or LIMIT or GROUP BY or ORDER BY clauses, and
559 ** if <table2> and <table1> are distinct tables but have identical
560 ** schemas, including all the same indices, then a special optimization
561 ** is invoked that copies raw records from <table2> over to <table1>.
562 ** See the xferOptimization() function for the implementation of this
563 ** template. This is the 2nd template.
564 **
565 ** open a write cursor to <table>
566 ** open read cursor on <table2>
567 ** transfer all records in <table2> over to <table>
568 ** close cursors
569 ** foreach index on <table>
570 ** open a write cursor on the <table> index
571 ** open a read cursor on the corresponding <table2> index
572 ** transfer all records from the read to the write cursors
573 ** close cursors
574 ** end foreach
575 **
576 ** The 3rd template is for when the second template does not apply
577 ** and the SELECT clause does not read from <table> at any time.
578 ** The generated code follows this template:
579 **
580 ** X <- A
581 ** goto B
582 ** A: setup for the SELECT
583 ** loop over the rows in the SELECT
584 ** load values into registers R..R+n
585 ** yield X
586 ** end loop
587 ** cleanup after the SELECT
588 ** end-coroutine X
589 ** B: open write cursor to <table> and its indices
590 ** C: yield X, at EOF goto D
591 ** insert the select result into <table> from R..R+n
592 ** goto C
593 ** D: cleanup
594 **
595 ** The 4th template is used if the insert statement takes its
596 ** values from a SELECT but the data is being inserted into a table
597 ** that is also read as part of the SELECT. In the third form,
598 ** we have to use an intermediate table to store the results of
599 ** the select. The template is like this:
600 **
601 ** X <- A
602 ** goto B
603 ** A: setup for the SELECT
604 ** loop over the tables in the SELECT
605 ** load value into register R..R+n
606 ** yield X
607 ** end loop
608 ** cleanup after the SELECT
609 ** end co-routine R
610 ** B: open temp table
611 ** L: yield X, at EOF goto M
612 ** insert row from R..R+n into temp table
613 ** goto L
614 ** M: open write cursor to <table> and its indices
615 ** rewind temp table
616 ** C: loop over rows of intermediate table
617 ** transfer values form intermediate table into <table>
618 ** end loop
619 ** D: cleanup
620 */
628 ){
652 /* Register allocations */
661 #ifndef SQLITE_OMIT_TRIGGER
665 #endif
670 }
673 /* If the Select object is really just a simple VALUES() list with a
674 ** single row (the common case) then keep that one row of values
675 ** and discard the other (unused) parts of the pSelect object
676 */
682 }
684 /* Locate the table into which we will be inserting new information.
685 */
690 }
696 }
699 /* Figure out if we have any triggers and if the table being
700 ** inserted into is a view
701 */
702 #ifndef SQLITE_OMIT_TRIGGER
705 #else
706 # define pTrigger 0
707 # define tmask 0
708 # define isView 0
709 #endif
710 #ifdef SQLITE_OMIT_VIEW
711 # undef isView
712 # define isView 0
713 #endif
716 /* If pTab is really a view, make sure it has been initialized.
717 ** ViewGetColumnNames() is a no-op if pTab is not a view.
718 */
721 }
723 /* Cannot insert into a read-only table.
724 */
727 }
729 /* Allocate a VDBE
730 */
736 #ifndef SQLITE_OMIT_XFER_OPT
737 /* If the statement is of the form
738 **
739 ** INSERT INTO <table1> SELECT * FROM <table2>;
740 **
741 ** Then special optimizations can be applied that make the transfer
742 ** very fast and which reduce fragmentation of indices.
743 **
744 ** This is the 2nd template.
745 */
750 }
753 /* If this is an AUTOINCREMENT table, look up the sequence number in the
754 ** sqlite_sequence table and store it in memory cell regAutoinc.
755 */
758 /* Allocate a block registers to hold the rowid and the values
759 ** for all columns of the new row.
760 */
764 regRowid++;
766 }
769 /* If the INSERT statement included an IDLIST term, then make sure
770 ** all elements of the IDLIST really are columns of the table and
771 ** remember the column indices.
772 **
773 ** If the table has an INTEGER PRIMARY KEY column and that column
774 ** is named in the IDLIST, then record in the ipkColumn variable
775 ** the index into IDLIST of the primary key column. ipkColumn is
776 ** the index of the primary key as it appears in IDLIST, not as
777 ** is appears in the original table. (The index of the INTEGER
778 ** PRIMARY KEY in the original table is pTab->iPKey.) After this
779 ** loop, if ipkColumn==(-1), that means that integer primary key
780 ** is unspecified, and hence the table is either WITHOUT ROWID or
781 ** it will automatically generated an integer primary key.
782 **
783 ** bIdListInOrder is true if the columns in IDLIST are in storage
784 ** order. This enables an optimization that avoids shuffling the
785 ** columns into storage order. False negatives are harmless,
786 ** but false positives will cause database corruption.
787 */
792 }
800 }
801 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
807 }
808 #endif
810 }
811 }
821 }
822 }
823 }
824 }
826 /* Figure out how many columns of data are supplied. If the data
827 ** is coming from a SELECT statement, then generate a co-routine that
828 ** produces a single row of the SELECT on each invocation. The
829 ** co-routine is the common header to the 3rd and 4th templates.
830 */
832 /* Data is coming from a SELECT or from a multi-row VALUES clause.
833 ** Generate a co-routine to run the SELECT. */
852 /* Set useTempTable to TRUE if the result of the SELECT statement
853 ** should be written into a temporary table (template 4). Set to
854 ** FALSE if each output row of the SELECT can be written directly into
855 ** the destination table (template 3).
856 **
857 ** A temp table must be used if the table being updated is also one
858 ** of the tables being read by the SELECT statement. Also use a
859 ** temp table in the case of row triggers.
860 */
863 }
866 /* Invoke the coroutine to extract information from the SELECT
867 ** and add it to a transient table srcTab. The code generated
868 ** here is from the 4th template:
869 **
870 ** B: open temp table
871 ** L: yield X, goto M at EOF
872 ** insert row from R..R+n into temp table
873 ** goto L
874 ** M: ...
875 */
892 }
894 /* This is the case if the data for the INSERT is coming from a
895 ** single-row VALUES clause
896 */
897 NameContext sNC;
906 }
909 }
910 }
912 /* If there is no IDLIST term but the table has an integer primary
913 ** key, the set the ipkColumn variable to the integer primary key
914 ** column index in the original table definition.
915 */
918 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
926 ipkColumn--;
927 }
928 }
929 }
930 #endif
931 }
933 /* Make sure the number of columns in the source data matches the number
934 ** of columns to be inserted into the table.
935 */
938 }
944 }
948 }
950 /* Initialize the count of rows to be inserted
951 */
955 ){
958 }
960 /* If this is not a view, open the table and and all indices */
968 }
973 }
975 }
976 #ifndef SQLITE_OMIT_UPSERT
982 }
986 }
989 }
997 }
998 }
999 #endif
1002 /* This is the top of the main insertion loop */
1004 /* This block codes the top of loop only. The complete loop is the
1005 ** following pseudocode (template 4):
1006 **
1007 ** rewind temp table, if empty goto D
1008 ** C: loop over rows of intermediate table
1009 ** transfer values form intermediate table into <table>
1010 ** end loop
1011 ** D: ...
1012 */
1016 /* This block codes the top of loop only. The complete loop is the
1017 ** following pseudocode (template 3):
1018 **
1019 ** C: yield X, at EOF goto D
1020 ** insert the select result into <table> from R..R+n
1021 ** goto C
1022 ** D: ...
1023 */
1028 /* tag-20191021-001: If the INTEGER PRIMARY KEY is being generated by the
1029 ** SELECT, go ahead and copy the value into the rowid slot now, so that
1030 ** the value does not get overwritten by a NULL at tag-20191021-002. */
1032 }
1033 }
1035 /* Compute data for ordinary columns of the new entry. Values
1036 ** are written in storage order into registers starting with regData.
1037 ** Only ordinary columns are computed in this loop. The rowid
1038 ** (if there is one) is computed later and generated columns are
1039 ** computed after the rowid since they might depend on the value
1040 ** of the rowid.
1041 */
1046 u32 colFlags;
1049 /* tag-20191021-002: References to the INTEGER PRIMARY KEY are filled
1050 ** using the rowid. So put a NULL in the IPK slot of the record to avoid
1051 ** using excess space. The file format definition requires this extra
1052 ** NULL - we cannot optimize further by skipping the column completely */
1055 }
1057 nHidden++;
1059 /* Virtual columns do not participate in OP_MakeRecord. So back up
1060 ** iRegStore by one slot to compensate for the iRegStore++ in the
1061 ** outer for() loop */
1062 iRegStore--;
1065 /* Stored columns are computed later. But if there are BEFORE
1066 ** triggers, the slots used for stored columns will be OP_Copy-ed
1067 ** to a second block of registers, so the register needs to be
1068 ** initialized to NULL to avoid an uninitialized register read */
1071 }
1074 /* Hidden columns that are not explicitly named in the INSERT
1075 ** get there default value */
1078 }
1079 }
1083 /* A column not named in the insert column list gets its
1084 ** default value */
1087 }
1090 /* This is INSERT INTO ... DEFAULT VALUES. Load the default value. */
1095 }
1102 }
1105 }
1106 }
1109 /* Run the BEFORE and INSTEAD OF triggers, if there are any
1110 */
1115 /* build the NEW.* reference row. Note that if there is an INTEGER
1116 ** PRIMARY KEY into which a NULL is being inserted, that NULL will be
1117 ** translated into a unique ID for the row. But on a BEFORE trigger,
1118 ** we do not know what the unique ID will be (because the insert has
1119 ** not happened yet) so we substitute a rowid of -1
1120 */
1131 }
1136 }
1138 /* Cannot have triggers on a virtual table. If it were possible,
1139 ** this block would have to account for hidden column.
1140 */
1143 /* Copy the new data already generated. */
1147 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
1148 /* Compute the new value for generated columns after all other
1149 ** columns have already been computed. This must be done after
1150 ** computing the ROWID in case one of the generated columns
1151 ** refers to the ROWID. */
1156 }
1157 #endif
1159 /* If this is an INSERT on a view with an INSTEAD OF INSERT trigger,
1160 ** do not attempt any conversions before assembling the record.
1161 ** If this is a real table, attempt conversions as required by the
1162 ** table column affinities.
1163 */
1166 }
1168 /* Fire BEFORE or INSTEAD OF triggers */
1173 }
1177 /* The row that the VUpdate opcode will delete: none */
1179 }
1181 /* Compute the new rowid */
1185 /* Rowid already initialized at tag-20191021-001 */
1193 }
1194 }
1195 /* If the PRIMARY KEY expression is NULL, then use OP_NewRowid
1196 ** to generate a unique primary key value.
1197 */
1207 }
1209 }
1215 }
1218 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
1219 /* Compute the new value for generated columns after all other
1220 ** columns have already been computed. This must be done after
1221 ** computing the ROWID in case one of the generated columns
1222 ** is derived from the INTEGER PRIMARY KEY. */
1225 }
1226 #endif
1228 /* Generate code to check constraints and generate index keys and
1229 ** do the insertion.
1230 */
1231 #ifndef SQLITE_OMIT_VIRTUALTABLE
1239 #endif
1240 {
1245 );
1248 /* Set the OPFLAG_USESEEKRESULT flag if either (a) there are no REPLACE
1249 ** constraints or (b) there are no triggers and this table is not a
1250 ** parent table in a foreign key constraint. It is safe to set the
1251 ** flag in the second case as if any REPLACE constraint is hit, an
1252 ** OP_Delete or OP_IdxDelete instruction will be executed on each
1253 ** cursor that is disturbed. And these instructions both clear the
1254 ** VdbeCursor.seekResult variable, disabling the OPFLAG_USESEEKRESULT
1255 ** functionality. */
1259 );
1260 }
1261 }
1263 /* Update the count of rows that are inserted
1264 */
1267 }
1270 /* Code AFTER triggers */
1273 }
1275 /* The bottom of the main insertion loop, if the data source
1276 ** is a SELECT statement.
1277 */
1285 #ifdef SQLITE_DEBUG
1286 /* If we are jumping back to an OP_Yield that is preceded by an
1287 ** OP_ReleaseReg, set the p5 flag on the OP_Goto so that the
1288 ** OP_ReleaseReg will be included in the loop. */
1292 }
1293 #endif
1295 }
1297 insert_end:
1298 /* Update the sqlite_sequence table by storing the content of the
1299 ** maximum rowid counter values recorded while inserting into
1300 ** autoincrement tables.
1301 */
1304 }
1306 /*
1307 ** Return the number of rows inserted. If this routine is
1308 ** generating code because of a call to sqlite3NestedParse(), do not
1309 ** invoke the callback function.
1310 */
1315 }
1317 insert_cleanup:
1324 }
1326 /* Make sure "isView" and other macros defined above are undefined. Otherwise
1327 ** they may interfere with compilation of other functions in this file
1328 ** (or in another file, if this file becomes part of the amalgamation). */
1329 #ifdef isView
1330 #undef isView
1331 #endif
1332 #ifdef pTrigger
1333 #undef pTrigger
1334 #endif
1335 #ifdef tmask
1336 #undef tmask
1337 #endif
1339 /*
1340 ** Meanings of bits in of pWalker->eCode for
1341 ** sqlite3ExprReferencesUpdatedColumn()
1342 */
1346 /* This is the Walker callback from sqlite3ExprReferencesUpdatedColumn().
1347 * Set bit 0x01 of pWalker->eCode if pWalker->eCode to 0 and if this
1348 ** expression node references any of the
1349 ** columns that are being modifed by an UPDATE statement.
1350 */
1357 }
1360 }
1361 }
1363 }
1365 /*
1366 ** pExpr is a CHECK constraint on a row that is being UPDATE-ed. The
1367 ** only columns that are modified by the UPDATE are those for which
1368 ** aiChng[i]>=0, and also the ROWID is modified if chngRowid is true.
1369 **
1370 ** Return true if CHECK constraint pExpr uses any of the
1371 ** changing columns (or the rowid if it is changing). In other words,
1372 ** return true if this CHECK constraint must be validated for
1373 ** the new row in the UPDATE statement.
1374 **
1375 ** 2018-09-15: pExpr might also be an expression for an index-on-expressions.
1376 ** The operation of this routine is the same - return true if an only if
1377 ** the expression uses one or more of columns identified by the second and
1378 ** third arguments.
1379 */
1384 ){
1385 Walker w;
1394 }
1400 }
1402 /*
1403 ** Generate code to do constraint checks prior to an INSERT or an UPDATE
1404 ** on table pTab.
1405 **
1406 ** The regNewData parameter is the first register in a range that contains
1407 ** the data to be inserted or the data after the update. There will be
1408 ** pTab->nCol+1 registers in this range. The first register (the one
1409 ** that regNewData points to) will contain the new rowid, or NULL in the
1410 ** case of a WITHOUT ROWID table. The second register in the range will
1411 ** contain the content of the first table column. The third register will
1412 ** contain the content of the second table column. And so forth.
1413 **
1414 ** The regOldData parameter is similar to regNewData except that it contains
1415 ** the data prior to an UPDATE rather than afterwards. regOldData is zero
1416 ** for an INSERT. This routine can distinguish between UPDATE and INSERT by
1417 ** checking regOldData for zero.
1418 **
1419 ** For an UPDATE, the pkChng boolean is true if the true primary key (the
1420 ** rowid for a normal table or the PRIMARY KEY for a WITHOUT ROWID table)
1421 ** might be modified by the UPDATE. If pkChng is false, then the key of
1422 ** the iDataCur content table is guaranteed to be unchanged by the UPDATE.
1423 **
1424 ** For an INSERT, the pkChng boolean indicates whether or not the rowid
1425 ** was explicitly specified as part of the INSERT statement. If pkChng
1426 ** is zero, it means that the either rowid is computed automatically or
1427 ** that the table is a WITHOUT ROWID table and has no rowid. On an INSERT,
1428 ** pkChng will only be true if the INSERT statement provides an integer
1429 ** value for either the rowid column or its INTEGER PRIMARY KEY alias.
1430 **
1431 ** The code generated by this routine will store new index entries into
1432 ** registers identified by aRegIdx[]. No index entry is created for
1433 ** indices where aRegIdx[i]==0. The order of indices in aRegIdx[] is
1434 ** the same as the order of indices on the linked list of indices
1435 ** at pTab->pIndex.
1436 **
1437 ** (2019-05-07) The generated code also creates a new record for the
1438 ** main table, if pTab is a rowid table, and stores that record in the
1439 ** register identified by aRegIdx[nIdx] - in other words in the first
1440 ** entry of aRegIdx[] past the last index. It is important that the
1441 ** record be generated during constraint checks to avoid affinity changes
1442 ** to the register content that occur after constraint checks but before
1443 ** the new record is inserted.
1444 **
1445 ** The caller must have already opened writeable cursors on the main
1446 ** table and all applicable indices (that is to say, all indices for which
1447 ** aRegIdx[] is not zero). iDataCur is the cursor for the main table when
1448 ** inserting or updating a rowid table, or the cursor for the PRIMARY KEY
1449 ** index when operating on a WITHOUT ROWID table. iIdxCur is the cursor
1450 ** for the first index in the pTab->pIndex list. Cursors for other indices
1451 ** are at iIdxCur+N for the N-th element of the pTab->pIndex list.
1452 **
1453 ** This routine also generates code to check constraints. NOT NULL,
1454 ** CHECK, and UNIQUE constraints are all checked. If a constraint fails,
1455 ** then the appropriate action is performed. There are five possible
1456 ** actions: ROLLBACK, ABORT, FAIL, REPLACE, and IGNORE.
1457 **
1458 ** Constraint type Action What Happens
1459 ** --------------- ---------- ----------------------------------------
1460 ** any ROLLBACK The current transaction is rolled back and
1461 ** sqlite3_step() returns immediately with a
1462 ** return code of SQLITE_CONSTRAINT.
1463 **
1464 ** any ABORT Back out changes from the current command
1465 ** only (do not do a complete rollback) then
1466 ** cause sqlite3_step() to return immediately
1467 ** with SQLITE_CONSTRAINT.
1468 **
1469 ** any FAIL Sqlite3_step() returns immediately with a
1470 ** return code of SQLITE_CONSTRAINT. The
1471 ** transaction is not rolled back and any
1472 ** changes to prior rows are retained.
1473 **
1474 ** any IGNORE The attempt in insert or update the current
1475 ** row is skipped, without throwing an error.
1476 ** Processing continues with the next row.
1477 ** (There is an immediate jump to ignoreDest.)
1478 **
1479 ** NOT NULL REPLACE The NULL value is replace by the default
1480 ** value for that column. If the default value
1481 ** is NULL, the action is the same as ABORT.
1482 **
1483 ** UNIQUE REPLACE The other row that conflicts with the row
1484 ** being inserted is removed.
1485 **
1486 ** CHECK REPLACE Illegal. The results in an exception.
1487 **
1488 ** Which action to take is determined by the overrideError parameter.
1489 ** Or if overrideError==OE_Default, then the pParse->onError parameter
1490 ** is used. Or if pParse->onError==OE_Default then the onError value
1491 ** for the constraint is used.
1492 */
1507 ){
1525 /* Variables associated with retesting uniqueness constraints after
1526 ** replace triggers fire have run */
1540 /* pPk is the PRIMARY KEY index for WITHOUT ROWID tables and NULL for
1541 ** normal rowid tables. nPkField is the number of key fields in the
1542 ** pPk index or 1 for a rowid table. In other words, nPkField is the
1543 ** number of fields in the true primary key of the table. */
1550 }
1552 /* Record that this module has started */
1556 /* Test all NOT NULL constraints.
1557 */
1571 }
1574 nGenerated++;
1576 }
1578 /* Do not check NOT NULL on columns that do not change */
1580 }
1585 }
1589 ){
1596 }
1599 }
1609 nSeenReplace++;
1613 }
1616 /* no break */ deliberate_fall_through
1627 }
1633 }
1637 /* If there are no generated columns with NOT NULL constraints
1638 ** and no NOT NULL ON CONFLICT REPLACE constraints, then a single
1639 ** pass is sufficient */
1641 }
1644 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
1646 /* If any NOT NULL ON CONFLICT REPLACE constraints fired on the
1647 ** first pass, recomputed values for all generated columns, as
1648 ** those values might depend on columns affected by the REPLACE.
1649 */
1651 }
1652 #endif
1656 /* Test all CHECK constraints
1657 */
1658 #ifndef SQLITE_OMIT_CHECK
1669 ){
1670 /* The check constraints do not reference any of the columns being
1671 ** updated so there is no point it verifying the check constraint */
1673 }
1677 }
1683 }
1693 P5_ConstraintCheck);
1694 }
1696 }
1698 }
1701 /* UNIQUE and PRIMARY KEY constraints should be handled in the following
1702 ** order:
1703 **
1704 ** (1) OE_Update
1705 ** (2) OE_Abort, OE_Fail, OE_Rollback, OE_Ignore
1706 ** (3) OE_Replace
1707 **
1708 ** OE_Fail and OE_Ignore must happen before any changes are made.
1709 ** OE_Update guarantees that only a single row will change, so it
1710 ** must happen before OE_Replace. Technically, OE_Abort and OE_Rollback
1711 ** could happen in any order, but they are grouped up front for
1712 ** convenience.
1713 **
1714 ** 2018-08-14: Ticket https://www.sqlite.org/src/info/908f001483982c43
1715 ** The order of constraints used to have OE_Update as (2) and OE_Abort
1716 ** and so forth as (1). But apparently PostgreSQL checks the OE_Update
1717 ** constraint before any others, so it had to be moved.
1718 **
1719 ** Constraint checking code is generated in this order:
1720 ** (A) The rowid constraint
1721 ** (B) Unique index constraints that do not have OE_Replace as their
1722 ** default conflict resolution strategy
1723 ** (C) Unique index that do use OE_Replace by default.
1724 **
1725 ** The ordering of (2) and (3) is accomplished by making sure the linked
1726 ** list of indexes attached to a table puts all OE_Replace indexes last
1727 ** in the list. See sqlite3CreateIndex() for where that happens.
1728 */
1732 /* An ON CONFLICT DO NOTHING clause, without a constraint-target.
1733 ** Make all unique constraint resolution be OE_Ignore */
1738 /* If the constraint-target uniqueness check must be run first.
1739 ** Jump to that uniqueness check now */
1742 }
1743 }
1745 /* Determine if it is possible that triggers (either explicitly coded
1746 ** triggers or FK resolution actions) might run as a result of deletes
1747 ** that happen when OE_Replace conflict resolution occurs. (Call these
1748 ** "replace triggers".) If any replace triggers run, we will need to
1749 ** recheck all of the uniqueness constraints after they have all run.
1750 ** But on the recheck, the resolution is OE_Abort instead of OE_Replace.
1751 **
1752 ** If replace triggers are a possibility, then
1753 **
1754 ** (1) Allocate register regTrigCnt and initialize it to zero.
1755 ** That register will count the number of replace triggers that
1756 ** fire. Constraint recheck only occurs if the number is positive.
1757 ** (2) Initialize pTrigger to the list of all DELETE triggers on pTab.
1758 ** (3) Initialize addrRecheck and lblRecheckOk
1759 **
1760 ** The uniqueness rechecking code will create a series of tests to run
1761 ** in a second pass. The addrRecheck and lblRecheckOk variables are
1762 ** used to link together these tests which are separated from each other
1763 ** in the generate bytecode.
1764 */
1766 /* There are not DELETE triggers nor FK constraints. No constraint
1767 ** rechecks are needed. */
1777 }
1779 /* Replace triggers might exist. Allocate the counter and
1780 ** initialize it to zero. */
1786 }
1787 }
1789 /* If rowid is changing, make sure the new rowid does not previously
1790 ** exist in the table.
1791 */
1795 /* Figure out what action to take in case of a rowid collision */
1801 }
1803 /* figure out whether or not upsert applies in this case */
1809 }
1810 }
1812 /* If the response to a rowid conflict is REPLACE but the response
1813 ** to some other UNIQUE constraint is FAIL or IGNORE, then we need
1814 ** to defer the running of the rowid conflict checking until after
1815 ** the UNIQUE constraints have run.
1816 */
1820 ){
1823 }
1826 /* pkChng!=0 does not mean that the rowid has changed, only that
1827 ** it might have changed. Skip the conflict logic below if the rowid
1828 ** is unchanged. */
1832 }
1834 /* Check to see if the new rowid already exists in the table. Skip
1835 ** the following conflict logic if it does not. */
1844 /* no break */ deliberate_fall_through
1845 }
1854 }
1856 /* If there are DELETE triggers on this table and the
1857 ** recursive-triggers flag is set, call GenerateRowDelete() to
1858 ** remove the conflicting row from the table. This will fire
1859 ** the triggers and remove both the table and index b-tree entries.
1860 **
1861 ** Otherwise, if there are no triggers or the recursive-triggers
1862 ** flag is not set, but the table has one or more indexes, call
1863 ** GenerateRowIndexDelete(). This removes the index b-tree entries
1864 ** only. The table b-tree entry will be replaced by the new entry
1865 ** when it is inserted.
1866 **
1867 ** If either GenerateRowDelete() or GenerateRowIndexDelete() is called,
1868 ** also invoke MultiWrite() to indicate that this VDBE may require
1869 ** statement rollback (if the statement is aborted after the delete
1870 ** takes place). Earlier versions called sqlite3MultiWrite() regardless,
1871 ** but being more selective here allows statements like:
1872 **
1873 ** REPLACE INTO t(rowid) VALUES($newrowid)
1874 **
1875 ** to run without a statement journal if there are no indexes on the
1876 ** table.
1877 */
1883 nReplaceTrig++;
1885 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
1887 /* This OP_Delete opcode fires the pre-update-hook only. It does
1888 ** not modify the b-tree. It is more efficient to let the coming
1889 ** OP_Insert replace the existing entry than it is to delete the
1890 ** existing entry and then insert a new one. */
1897 }
1898 }
1901 }
1902 #ifndef SQLITE_OMIT_UPSERT
1905 /* no break */ deliberate_fall_through
1906 }
1907 #endif
1912 }
1913 }
1918 }
1919 }
1921 /* Test all UNIQUE constraints by creating entries for each UNIQUE
1922 ** index and making sure that duplicate entries do not already exist.
1923 ** Compute the revised record entries for indices as we go.
1924 **
1925 ** This loop also handles the case of the PRIMARY KEY index for a
1926 ** WITHOUT ROWID table.
1927 */
1943 }
1947 }
1952 /* Skip partial indices for which the WHERE clause is not true */
1957 SQLITE_JUMPIFNULL);
1959 }
1961 /* Create a record for this index entry as it should appear after
1962 ** the insert or update. Store that record in the aRegIdx[ix] register
1963 */
1982 }
1983 }
1986 #ifdef SQLITE_ENABLE_NULL_TRIM
1989 }
1990 #endif
1993 /* In an UPDATE operation, if this index is the PRIMARY KEY index
1994 ** of a WITHOUT ROWID table and there has been no change the
1995 ** primary key, then no collision is possible. The collision detection
1996 ** logic below can all be skipped. */
2000 }
2002 /* Find out what action to take in case there is a uniqueness conflict */
2007 }
2012 }
2014 /* Figure out if the upsert clause applies to this index */
2020 }
2021 }
2023 /* Collision detection may be omitted if all of the following are true:
2024 ** (1) The conflict resolution algorithm is REPLACE
2025 ** (2) The table is a WITHOUT ROWID table
2026 ** (3) There are no secondary indexes on the table
2027 ** (4) No delete triggers need to be fired if there is a conflict
2028 ** (5) No FK constraint counters need to be updated if a conflict occurs.
2029 **
2030 ** This is not possible for ENABLE_PREUPDATE_HOOK builds, as the row
2031 ** must be explicitly deleted in order to ensure any pre-update hook
2032 ** is invoked. */
2033 #ifndef SQLITE_ENABLE_PREUPDATE_HOOK
2041 ){
2044 }
2047 /* Check to see if the new index entry will be unique */
2049 addrConflictCk =
2053 /* Generate code to handle collisions */
2058 /* Conflict only if the rowid of the existing index entry
2059 ** is different from old-rowid */
2064 }
2067 /* Extract the PRIMARY KEY from the end of the index entry and
2068 ** store it in registers regR..regR+nPk-1 */
2076 }
2077 }
2079 /* If currently processing the PRIMARY KEY of a WITHOUT ROWID
2080 ** table, only conflict if the new PRIMARY KEY values are actually
2081 ** different from the old.
2082 **
2083 ** For a UNIQUE index, only conflict if the PRIMARY KEY values
2084 ** of the matched index row are different from the original PRIMARY
2085 ** KEY values of this row before the update. */
2097 }
2101 );
2105 }
2106 }
2107 }
2108 }
2110 /* Generate code that executes if the new index entry is not unique */
2122 }
2123 #ifndef SQLITE_OMIT_UPSERT
2126 /* no break */ deliberate_fall_through
2127 }
2128 #endif
2133 }
2143 nReplaceTrig++;
2144 }
2147 }
2153 }
2161 /* Here we insert code that will be invoked after all constraint
2162 ** checks have run, if and only if one or more replace triggers
2163 ** fired. */
2167 /* Bypass the recheck if this partial index is not defined
2168 ** for the current row */
2171 }
2172 /* Copy the constraint check code from above, except change
2173 ** the constraint-ok jump destination to be the address of
2174 ** the next retest block */
2177 /* The sqlite3VdbeAddOp4() call might reallocate the opcode array.
2178 ** Hence, make a complete copy of the opcode, rather than using
2179 ** a pointer to the opcode. */
2188 }
2193 }
2194 nConflictCk--;
2195 addrConflictCk++;
2196 }
2197 /* If the retest fails, issue an abort */
2201 }
2204 }
2205 }
2211 }
2213 }
2215 /* If the IPK constraint is a REPLACE, run it last */
2220 }
2222 /* Recheck all uniqueness constraints after replace triggers have run */
2232 }
2238 }
2240 }
2242 /* Generate the table record */
2249 }
2250 }
2254 }
2256 #ifdef SQLITE_ENABLE_NULL_TRIM
2257 /*
2258 ** Change the P5 operand on the last opcode (which should be an OP_MakeRecord)
2259 ** to be the number of columns in table pTab that must not be NULL-trimmed.
2260 **
2261 ** Or if no columns of pTab may be NULL-trimmed, leave P5 at zero.
2262 */
2264 u16 i;
2266 /* Records with omitted columns are only allowed for schema format
2267 ** version 2 and later (SQLite version 3.1.4, 2005-02-20). */
2273 }
2275 }
2276 #endif
2278 /*
2279 ** This routine generates code to finish the INSERT or UPDATE operation
2280 ** that was started by a prior call to sqlite3GenerateConstraintChecks.
2281 ** A consecutive range of registers starting at regNewData contains the
2282 ** rowid and the content to be inserted.
2283 **
2284 ** The arguments to this routine should be the same as the first six
2285 ** arguments to sqlite3GenerateConstraintChecks.
2286 */
2297 ){
2306 );
2312 /* All REPLACE indexes are at the end of the list */
2320 }
2326 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
2332 );
2335 }
2336 #endif
2337 }
2342 }
2349 }
2352 }
2355 }
2359 }
2361 }
2363 /*
2364 ** Allocate cursors for the pTab table and all its indices and generate
2365 ** code to open and initialized those cursors.
2366 **
2367 ** The cursor for the object that contains the complete data (normally
2368 ** the table itself, but the PRIMARY KEY index in the case of a WITHOUT
2369 ** ROWID table) is returned in *piDataCur. The first index cursor is
2370 ** returned in *piIdxCur. The number of indices is returned.
2371 **
2372 ** Use iBase as the first cursor (either the *piDataCur for rowid tables
2373 ** or the first index for WITHOUT ROWID tables) if it is non-negative.
2374 ** If iBase is negative, then allocate the next available cursor.
2375 **
2376 ** For a rowid table, *piDataCur will be exactly one less than *piIdxCur.
2377 ** For a WITHOUT ROWID table, *piDataCur will be somewhere in the range
2378 ** of *piIdxCurs, depending on where the PRIMARY KEY index appears on the
2379 ** pTab->pIndex list.
2380 **
2381 ** If pTab is a virtual table, then this routine is a no-op and the
2382 ** *piDataCur and *piIdxCur values are left uninitialized.
2383 */
2393 ){
2403 /* This routine is a no-op for virtual tables. Leave the output
2404 ** variables *piDataCur and *piIdxCur uninitialized so that valgrind
2405 ** can detect if they are used by mistake in the caller. */
2407 }
2418 }
2426 }
2432 }
2433 }
2436 }
2439 #ifdef SQLITE_TEST
2440 /*
2441 ** The following global variable is incremented whenever the
2442 ** transfer optimization is used. This is used for testing
2443 ** purposes only - to make sure the transfer optimization really
2444 ** is happening when it is supposed to.
2445 */
2450 #ifndef SQLITE_OMIT_XFER_OPT
2451 /*
2452 ** Check to see if index pSrc is compatible as a source of data
2453 ** for index pDest in an insert transfer optimization. The rules
2454 ** for a compatible index:
2455 **
2456 ** * The index is over the same set of columns
2457 ** * The same DESC and ASC markings occurs on all columns
2458 ** * The same onError processing (OE_Abort, OE_Ignore, etc)
2459 ** * The same collating sequence on each column
2460 ** * The index has the exact same WHERE clause
2461 */
2468 }
2471 }
2475 }
2481 }
2482 }
2485 }
2488 }
2489 }
2492 }
2494 /* If no test above fails then the indices must be compatible */
2496 }
2498 /*
2499 ** Attempt the transfer optimization on INSERTs of the form
2500 **
2501 ** INSERT INTO tab1 SELECT * FROM tab2;
2502 **
2503 ** The xfer optimization transfers raw records from tab2 over to tab1.
2504 ** Columns are not decoded and reassembled, which greatly improves
2505 ** performance. Raw index records are transferred in the same way.
2506 **
2507 ** The xfer optimization is only attempted if tab1 and tab2 are compatible.
2508 ** There are lots of rules for determining compatibility - see comments
2509 ** embedded in the code for details.
2510 **
2511 ** This routine returns TRUE if the optimization is guaranteed to be used.
2512 ** Sometimes the xfer optimization will only work if the destination table
2513 ** is empty - a factor that can only be determined at run-time. In that
2514 ** case, this routine generates code for the xfer optimization but also
2515 ** does a test to see if the destination table is empty and jumps over the
2516 ** xfer optimization code if the test fails. In that case, this routine
2517 ** returns FALSE so that the caller will know to go ahead and generate
2518 ** an unoptimized transfer. This routine also returns FALSE if there
2519 ** is no chance that the xfer optimization can be applied.
2520 **
2521 ** This optimization is particularly useful at making VACUUM run faster.
2522 */
2529 ){
2548 }
2550 /* Do not attempt to process this query if there are an WITH clauses
2551 ** attached to it. Proceeding may generate a false "no such table: xxx"
2552 ** error if pSelect reads from a CTE named "xxx". */
2554 }
2557 }
2558 #ifndef SQLITE_OMIT_VIRTUALTABLE
2561 }
2562 #endif
2566 }
2570 }
2573 }
2576 }
2579 }
2580 /* Do not need to test for a HAVING clause. If HAVING is present but
2581 ** there is no ORDER BY, we will get an error. */
2584 }
2587 }
2590 }
2593 }
2598 }
2602 }
2604 /* At this point we have established that the statement is of the
2605 ** correct syntactic form to participate in this optimization. Now
2606 ** we have to check the semantics.
2607 */
2612 }
2616 }
2619 }
2620 #ifndef SQLITE_OMIT_VIRTUALTABLE
2623 }
2624 #endif
2627 }
2630 }
2633 }
2637 #ifdef SQLITE_ENABLE_HIDDEN_COLUMNS
2640 ){
2642 }
2643 #endif
2644 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
2645 /* Even if tables t1 and t2 have identical schemas, if they contain
2646 ** generated columns, then this statement is semantically incorrect:
2647 **
2648 ** INSERT INTO t2 SELECT * FROM t1;
2649 **
2650 ** The reason is that generated column values are returned by the
2651 ** the SELECT statement on the right but the INSERT statement on the
2652 ** left wants them to be omitted.
2653 **
2654 ** Nevertheless, this is a useful notational shorthand to tell SQLite
2655 ** to do a bulk transfer all of the content from t1 over to t2.
2656 **
2657 ** We could, in theory, disable this (except for internal use by the
2658 ** VACUUM command where it is actually needed). But why do that? It
2659 ** seems harmless enough, and provides a useful service.
2660 */
2664 }
2665 /* But the transfer is only allowed if both the source and destination
2666 ** tables have the exact same expressions for generated columns.
2667 ** This requirement could be relaxed for VIRTUAL columns, I suppose.
2668 */
2674 }
2675 }
2676 #endif
2679 }
2682 }
2685 }
2686 /* Default values for second and subsequent columns need to match. */
2693 ){
2695 }
2696 }
2697 }
2701 }
2704 }
2707 }
2710 /* The sqlite3FaultSim() call allows this corruption test to be
2711 ** bypassed during testing, in order to exercise other corruption tests
2712 ** further downstream. */
2714 }
2715 }
2716 #ifndef SQLITE_OMIT_CHECK
2719 }
2720 #endif
2721 #ifndef SQLITE_OMIT_FOREIGN_KEY
2722 /* Disallow the transfer optimization if the destination table constains
2723 ** any foreign key constraints. This is more restrictive than necessary.
2724 ** But the main beneficiary of the transfer optimization is the VACUUM
2725 ** command, and the VACUUM command disables foreign key constraints. So
2726 ** the extra complication to make this rule less restrictive is probably
2727 ** not worth the effort. Ticket [6284df89debdfa61db8073e062908af0c9b6118e]
2728 */
2731 }
2732 #endif
2735 }
2737 /* If we get this far, it means that the xfer optimization is at
2738 ** least a possibility, though it might only work if the destination
2739 ** table (tab1) is initially empty.
2740 */
2741 #ifdef SQLITE_TEST
2742 sqlite3_xferopt_count++;
2743 #endif
2758 )){
2759 /* In some circumstances, we are able to run the xfer optimization
2760 ** only if the destination table is initially empty. Unless the
2761 ** DBFLAG_Vacuum flag is set, this block generates code to make
2762 ** that determination. If DBFLAG_Vacuum is set, then the destination
2763 ** table is always empty.
2764 **
2765 ** Conditions under which the destination must be empty:
2766 **
2767 ** (1) There is no INTEGER PRIMARY KEY but there are indices.
2768 ** (If the destination is not initially empty, the rowid fields
2769 ** of index entries might need to change.)
2770 **
2771 ** (2) The destination has a unique index. (The xfer optimization
2772 ** is unable to test uniqueness.)
2773 **
2774 ** (3) onError is something other than OE_Abort and OE_Rollback.
2775 */
2779 }
2781 u8 insFlags;
2797 }
2803 }
2814 }
2819 }
2830 /* This INSERT command is part of a VACUUM operation, which guarantees
2831 ** that the destination table is empty. If all indexed columns use
2832 ** collation sequence BINARY, then it can also be assumed that the
2833 ** index will be populated by inserting keys in strictly sorted
2834 ** order. In this case, instead of seeking within the b-tree as part
2835 ** of every OP_IdxInsert opcode, an OP_SeekEnd is added before the
2836 ** OP_IdxInsert to seek to the point within the b-tree where each key
2837 ** should be inserted. This is faster.
2838 **
2839 ** If any of the indexed columns use a collation sequence other than
2840 ** BINARY, this optimization is disabled. This is because the user
2841 ** might change the definition of a collation sequence and then run
2842 ** a VACUUM command. In that case keys may not be written in strictly
2843 ** sorted order. */
2847 }
2851 }
2854 }
2862 }
2874 }
2875 }