lib/pkp/classes/db/SQLParser.inc.php

   1 <?php
   2
   3 /**
   4  * @file classes/db/SQLParser.inc.php
   5  *
   6  * Copyright (c) 2000-2009 John Willinsky
   7  * Distributed under the GNU GPL v2. For full terms see the file docs/COPYING.
   8  *
   9  * @class SQLParser
  10  * @ingroup db
  11  *
  12  * @brief Class for parsing and executing statements in SQL files.
  13  */
  14
  15 // $Id: SQLParser.inc.php,v 1.3 2009/04/08 21:34:54 asmecher Exp $
  16
  17
  18 class SQLParser {
  19
  20         /** @var $driver string The database driver */
  21         var $driver;
  22
  23         /** @var $dataSource object The database connection object */
  24         var $dataSource;
  25
  26         /** @var $debug boolean Enable debugging (print SQL statements as they are executed) */
  27         var $debug;
  28
  29         /** @var $errorMsg string Error message */
  30         var $errorMsg;
  31
  32         /** @var $commentDelim string Delimiter for SQL comments used by the data source */
  33         var $commentDelim;
  34
  35         /** @var $statementDelim string Delimiter for SQL statements used by the data source */
  36         var $statementDelim;
  37
  38         /**
  39          * Constructor.
  40          * @param $driver string the database driver (currently only "mysql" is supported)
  41          * @param $debug boolean echo each statement as it's executed
  42          */
  43         function SQLParser($driver, &$dataSource, $debug = false) {
  44                 $this->driver = $driver;
  45                 $this->dataSource =& $dataSource;
  46                 $this->debug = $debug;
  47                 $this->errorMsg = array();
  48                 $this->commentDelim = '(\-\-|#)';
  49                 $this->statementDelim = ';';
  50         }
  51
  52         /**
  53          * Parse an SQL file and execute all SQL statements in it.
  54          * @param $file string full path to the file
  55          * @param $failOnError boolean stop execution if an error is encountered
  56          * @return boolean true if no errors occurred, false otherwise
  57          */
  58         function executeFile($file, $failOnError = true) {
  59                 if (!file_exists($file) || !is_readable($file)) {
  60                         array_push($this->errorMsg, "$file does not exist or is not readble!");
  61                         return false;
  62                 }
  63
  64                 // Read file and break up into SQL statements
  65                 $sql = join('', file($file));
  66                 $this->stripComments($sql);
  67                 $statements =& $this->parseStatements($sql);
  68
  69                 // Execute each SQL statement
  70                 for ($i=0, $count=count($statements); $i < $count; $i++) {
  71                         if ($this->debug) {
  72                                 echo 'Executing: ', $statements[$i], "\n\n";
  73                         }
  74
  75                         $this->dataSource->execute($statements[$i]);
  76
  77                         if ($this->dataSource->errorNo() != 0) {
  78                                 // An error occurred executing the statement
  79                                 array_push($this->errorMsg, $this->dataSource->errorMsg());
  80
  81                                 if ($failOnError) {
  82                                         // Abort if fail on error is enabled
  83                                         return false;
  84                                 } else {
  85                                         $error = true;
  86                                 }
  87                         }
  88                 }
  89
  90                 return isset($error) ? false : true;
  91         }
  92
  93         /**
  94          * Strip SQL comments from SQL string.
  95          * @param $sql string
  96          */
  97         function stripComments(&$sql) {
  98                 $sql = trim(String::regexp_replace(sprintf('/^\s*%s(.*)$/m', $this->commentDelim), '', $sql));
  99         }
 100
 101         /**
 102          * Parse SQL content into individual SQL statements.
 103          * @param $sql string
 104          * @return array
 105          */
 106         function &parseStatements(&$sql) {
 107                 $statements = array();
 108                 $statementsTmp = explode($this->statementDelim, $sql);
 109
 110                 $currentStatement = '';
 111                 $numSingleQuotes = $numEscapedSingleQuotes = 0;
 112
 113                 // This method for parsing the SQL statements was adapted from one used in phpBB (http://www.phpbb.com/)
 114                 for ($i=0, $count=count($statementsTmp); $i < $count; $i++) {
 115                         // Get total number of single quotes in string
 116                         $numSingleQuotes += String::substr_count($statementsTmp[$i], "'");
 117
 118                         // Get number of escaped single quotes
 119                         $numEscapedSingleQuotes += String::regexp_match_all("/(?<!\\\\)(\\\\\\\\)*\\\\'/", $statementsTmp[$i], $matches);
 120
 121                         $currentStatement .= $statementsTmp[$i];
 122
 123                         if (($numSingleQuotes - $numEscapedSingleQuotes) % 2 == 0) {
 124                                 // Even number of unescaped single quotes, so statement must be complete
 125                                 if (trim($currentStatement) !== '') {
 126                                         array_push($statements, trim($currentStatement));
 127                                 }
 128                                 $currentStatement = '';
 129                                 $numSingleQuotes = $numEscapedSingleQuotes = 0;
 130
 131                         } else {
 132                                 // The statement is not complete, the delimiter must be inside the statement
 133                                 $currentStatement .= $this->statementDelim;
 134                         }
 135                 }
 136
 137                 return $statements;
 138         }
 139
 140         /**
 141          * Return the last error message that occurred in parsing.
 142          * @return string
 143          */
 144         function getErrorMsg() {
 145                 return count($this->errorMsg) == 0 ? null : array_pop($this->errorMsg);
 146         }
 147 }
 148
 149 ?>