includes/sql_parse.php
author Dan
Thu, 17 Dec 2009 04:27:50 -0500
changeset 1168 277a9cdead3e
parent 1081 745200a9cc2a
child 1227 bdac73ed481e
permissions -rw-r--r--
Namespace_Default: added a workaround for an inconsistency in SQL. Basically, if you join the same table multiple times under multiple aliases, COUNT() always uses the first instance. Was affecting the comment counter in the "discussion" button.

<?php

/*
 * Enano - an open-source CMS capable of wiki functions, Drupal-like sidebar blocks, and everything in between
 * Copyright (C) 2006-2009 Dan Fuhry
 * Installation package
 * sql_parse.php - SQL query splitter and templater
 *
 * This program is Free Software; you can redistribute and/or modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for details.
 */

/**
 * Parses a full file of SQL into individual queries. Also includes substitution (template) functions.
 * @package Enano
 * @subpackage Installer
 * @author Dan Fuhry
 */

class SQL_Parser
{
  /**
   * The SQL to be parsed.
   * @var string
   * @access private
   */
  
  private $sql_string;
  
  /**
   * Parsed SQL array
   * @var array
   * @access private
   */
  
  private $sql_array;
  
  /**
   * Template variables.
   * @var array
   * @access private
   */
  
  private $tpl_strings;
  
  /**
   * Constructor.
   * @param string If this contains newlines, it will be treated as the target SQL. If not, will be treated as a filename.
   * @param string If true, force as raw SQL, i.e. don't treat as a filename no matter what
   */
  
  public function __construct($sql, $force_file = false)
  {
    if ( strpos($sql, "\n") || $force_file )
    {
      $this->sql_string = $sql;
    }
    else
    {
      if ( file_exists($sql) )
      {
        $this->sql_string = @file_get_contents($sql);
        if ( empty($this->sql_string) )
        {
          throw new Exception('SQL file is blank or permissions are bad');
        }
      }
      else
      {
        throw new Exception('SQL file doesn\'t exist');
      }
      
    }
    $this->sql_array = false;
    $this->tpl_strings = array();
    
    // convert \r\n in the schema to \n, in case some FTP client or zip utility ran unix2dos for us
    // thanks to InvisGhost for reporting this error
    $this->sql_string = str_replace("\r\n", "\n", $this->sql_string);
  }
  
  /**
   * Sets template variables.
   * @param array Associative array of template variables to assign
   */
  
  public function assign_vars($vars)
  {
    if ( !is_array($vars) )
      return false;
    $this->tpl_strings = array_merge($this->tpl_strings, $vars);
  }
  
  /**
   * Internal function to parse the SQL.
   * @access private
   */
  
  private function parse_sql()
  {
    $this->sql_array = $this->sql_string;
    foreach ( $this->tpl_strings as $key => $value )
    {
      $this->sql_array = str_replace("{{{$key}}}", $value, $this->sql_array);
    }
    
    // Strip out comments
    $this->sql_array = explode("\n", $this->sql_array);
    
    foreach ( $this->sql_array as $i => $sql )
    {
      $query =& $this->sql_array[$i];
      $t = trim($query);
      if ( preg_match('/^(\#|--)/i', $t) )
      {
        unset($this->sql_array[$i]);
        unset($query);
      }
    }
    unset($query);
    
    $this->sql_array = array_values($this->sql_array);
    $this->sql_array = implode("\n", $this->sql_array);
    $this->sql_array = explode(";\n", trim($this->sql_array));
    
    foreach ( $this->sql_array as $i => $sql )
    {
      $query =& $this->sql_array[$i];
      $query = trim($query);
      if ( substr($query, ( strlen($query) - 1 ), 1 ) != ';' )
      {
        $query .= ';';
      }
    }
    unset($query);
  }
  
  /**
   * Returns the parsed array of SQL queries.
   * @param bool Optional. Defaults to false. If true, a parse is performed even if it already happened.
   * @return array
   */
  
  public function parse($force_reparse = false)
  {
    if ( !$this->sql_array || $force_reparse )
      $this->parse_sql();
    return $this->sql_array;
  }
}

?>