WordPress/wp-includes/wp-db.php

<?php
//  WordPress DB Class

//  ORIGINAL CODE FROM:
//  Justin Vincent (justin@visunet.ie)
//	http://php.justinvincent.com

define('EZSQL_VERSION', 'WP1.25');
define('OBJECT', 'OBJECT', true);
define('ARRAY_A', 'ARRAY_A', false);
define('ARRAY_N', 'ARRAY_N', false);

if (!defined('SAVEQUERIES'))
	define('SAVEQUERIES', false);

class wpdb {

	var $show_errors = true;
	var $num_queries = 0;
	var $last_query;
	var $col_info;
	var $queries;

	// Our tables
	var $posts;
	var $users;
	var $categories;
	var $post2cat;
	var $comments;
	var $links;
	var $options;
	var $optiontypes;
	var $optionvalues;
	var $optiongroups;
	var $optiongroup_options;
	var $postmeta;
	var $usermeta;
	var $terms;
	var $term_taxonomy;
	var $term_relationships;

	var $charset;
	var $collate;

	/**
	 * Connects to the database server and selects a database
	 * @param string $dbuser
	 * @param string $dbpassword
	 * @param string $dbname
	 * @param string $dbhost
	 */
	function wpdb($dbuser, $dbpassword, $dbname, $dbhost) {
		return $this->__construct($dbuser, $dbpassword, $dbname, $dbhost);
	}

	function __construct($dbuser, $dbpassword, $dbname, $dbhost) {
		register_shutdown_function(array(&$this, "__destruct"));

		if ( defined('DB_CHARSET') )
			$this->charset = DB_CHARSET;

		if ( defined('DB_COLLATE') )
			$this->collate = DB_COLLATE;

		$this->dbh = @mysql_connect($dbhost, $dbuser, $dbpassword);
		if (!$this->dbh) {
			$this->bail("
<h1>Error establishing a database connection</h1>
<p>This either means that the username and password information in your <code>wp-config.php</code> file is incorrect or we can't contact the database server at <code>$dbhost</code>. This could mean your host's database server is down.</p>
<ul>
	<li>Are you sure you have the correct username and password?</li>
	<li>Are you sure that you have typed the correct hostname?</li>
	<li>Are you sure that the database server is running?</li>
</ul>
<p>If you're unsure what these terms mean you should probably contact your host. If you still need help you can always visit the <a href='http://wordpress.org/support/'>WordPress Support Forums</a>.</p>
");
		}

		if ( !empty($this->charset) && version_compare(mysql_get_server_info(), '4.1.0', '>=') )
 			$this->query("SET NAMES '$this->charset'");

		$this->select($dbname);
	}

	function __destruct() {
		return true;
	}

	/**
	 * Selects a database using the current class's $this->dbh
	 * @param string $db name
	 */
	function select($db) {
		if (!@mysql_select_db($db, $this->dbh)) {
			$this->bail("
<h1>Can&#8217;t select database</h1>
<p>We were able to connect to the database server (which means your username and password is okay) but not able to select the <code>$db</code> database.</p>
<ul>
<li>Are you sure it exists?</li>
<li>On some systems the name of your database is prefixed with your username, so it would be like username_wordpress. Could that be the problem?</li>
</ul>
<p>If you don't know how to setup a database you should <strong>contact your host</strong>. If all else fails you may find help at the <a href='http://wordpress.org/support/'>WordPress Support Forums</a>.</p>");
		}
	}

	/**
	 * Escapes content for insertion into the database, for security
	 *
	 * @param string $string
	 * @return string query safe string
	 */
	function escape($string) {
		return addslashes( $string ); // Disable rest for now, causing problems
		if( !$this->dbh || version_compare( phpversion(), '4.3.0' ) == '-1' )
			return mysql_escape_string( $string );
		else
			return mysql_real_escape_string( $string, $this->dbh );
	}

	/**
	 * Escapes content by reference for insertion into the database, for security
	 * @param string $s
	 */
	function escape_by_ref(&$s) {
		$s = $this->escape($s);
	}

	/**
	 * Prepares a SQL query for safe use, using sprintf() syntax
	 */
	function prepare($args=NULL) {
		if ( NULL === $args )
			return;
		$args = func_get_args();
		$query = array_shift($args);
		$query = str_replace("'%s'", '%s', $query); // in case someone mistakenly already singlequoted it
		$query = str_replace('"%s"', '%s', $query); // doublequote unquoting
		$query = str_replace('%s', "'%s'", $query); // quote the strings
		array_walk($args, array(&$this, 'escape_by_ref'));
		return @vsprintf($query, $args);
	}

	// ==================================================================
	//	Print SQL/DB error.

	function print_error($str = '') {
		global $EZSQL_ERROR;
		if (!$str) $str = mysql_error($this->dbh);
		$EZSQL_ERROR[] =
		array ('query' => $this->last_query, 'error_str' => $str);

		$str = htmlspecialchars($str, ENT_QUOTES);
		$query = htmlspecialchars($this->last_query, ENT_QUOTES);
		// Is error output turned on or not..
		if ( $this->show_errors ) {
			// If there is an error then take note of it
			print "<div id='error'>
			<p class='wpdberror'><strong>WordPress database error:</strong> [$str]<br />
			<code>$query</code></p>
			</div>";
		} else {
			return false;
		}
	}

	// ==================================================================
	//	Turn error handling on or off..

	function show_errors() {
		$this->show_errors = true;
	}

	function hide_errors() {
		$this->show_errors = false;
	}

	// ==================================================================
	//	Kill cached query results

	function flush() {
		$this->last_result = array();
		$this->col_info = null;
		$this->last_query = null;
	}

	// ==================================================================
	//	Basic Query	- see docs for more detail

	function query($query) {
		// filter the query, if filters are available
		// NOTE: some queries are made before the plugins have been loaded, and thus cannot be filtered with this method
		if ( function_exists('apply_filters') )
			$query = apply_filters('query', $query);

		// initialise return
		$return_val = 0;
		$this->flush();

		// Log how the function was called
		$this->func_call = "\$db->query(\"$query\")";

		// Keep track of the last query for debug..
		$this->last_query = $query;

		// Perform the query via std mysql_query function..
		if (SAVEQUERIES)
			$this->timer_start();

		$this->result = @mysql_query($query, $this->dbh);
		++$this->num_queries;

		if (SAVEQUERIES)
			$this->queries[] = array( $query, $this->timer_stop() );

		// If there is an error then take note of it..
		if ( mysql_error($this->dbh) ) {
			$this->print_error();
			return false;
		}

		if ( preg_match("/^\\s*(insert|delete|update|replace) /i",$query) ) {
			$this->rows_affected = mysql_affected_rows($this->dbh);
			// Take note of the insert_id
			if ( preg_match("/^\\s*(insert|replace) /i",$query) ) {
				$this->insert_id = mysql_insert_id($this->dbh);
			}
			// Return number of rows affected
			$return_val = $this->rows_affected;
		} else {
			$i = 0;
			while ($i < @mysql_num_fields($this->result)) {
				$this->col_info[$i] = @mysql_fetch_field($this->result);
				$i++;
			}
			$num_rows = 0;
			while ( $row = @mysql_fetch_object($this->result) ) {
				$this->last_result[$num_rows] = $row;
				$num_rows++;
			}

			@mysql_free_result($this->result);

			// Log number of rows the query returned
			$this->num_rows = $num_rows;

			// Return number of rows selected
			$return_val = $this->num_rows;
		}

		return $return_val;
	}

	/**
	 * Get one variable from the database
	 * @param string $query (can be null as well, for caching, see codex)
	 * @param int $x = 0 row num to return
	 * @param int $y = 0 col num to return
	 * @return mixed results
	 */
	function get_var($query=null, $x = 0, $y = 0) {
		$this->func_call = "\$db->get_var(\"$query\",$x,$y)";
		if ( $query )
			$this->query($query);

		// Extract var out of cached results based x,y vals
		if ( $this->last_result[$y] ) {
			$values = array_values(get_object_vars($this->last_result[$y]));
		}

		// If there is a value return it else return null
		return (isset($values[$x]) && $values[$x]!=='') ? $values[$x] : null;
	}

	/**
	 * Get one row from the database
	 * @param string $query
	 * @param string $output ARRAY_A | ARRAY_N | OBJECT
	 * @param int $y row num to return
	 * @return mixed results
	 */
	function get_row($query = null, $output = OBJECT, $y = 0) {
		$this->func_call = "\$db->get_row(\"$query\",$output,$y)";
		if ( $query )
			$this->query($query);
		else
			return null;

		if ( !isset($this->last_result[$y]) )
			return null;

		if ( $output == OBJECT ) {
			return $this->last_result[$y] ? $this->last_result[$y] : null;
		} elseif ( $output == ARRAY_A ) {
			return $this->last_result[$y] ? get_object_vars($this->last_result[$y]) : null;
		} elseif ( $output == ARRAY_N ) {
			return $this->last_result[$y] ? array_values(get_object_vars($this->last_result[$y])) : null;
		} else {
			$this->print_error(" \$db->get_row(string query, output type, int offset) -- Output type must be one of: OBJECT, ARRAY_A, ARRAY_N");
		}
	}

	/**
	 * Gets one column from the database
	 * @param string $query (can be null as well, for caching, see codex)
	 * @param int $x col num to return
	 * @return array results
	 */
	function get_col($query = null , $x = 0) {
		if ( $query )
			$this->query($query);

		$new_array = array();
		// Extract the column values
		for ( $i=0; $i < count($this->last_result); $i++ ) {
			$new_array[$i] = $this->get_var(null, $x, $i);
		}
		return $new_array;
	}

	/**
	 * Return an entire result set from the database
	 * @param string $query (can also be null to pull from the cache)
	 * @param string $output ARRAY_A | ARRAY_N | OBJECT
	 * @return mixed results
	 */
	function get_results($query = null, $output = OBJECT) {
		$this->func_call = "\$db->get_results(\"$query\", $output)";

		if ( $query )
			$this->query($query);
		else
			return null;

		// Send back array of objects. Each row is an object
		if ( $output == OBJECT ) {
			return $this->last_result;
		} elseif ( $output == ARRAY_A || $output == ARRAY_N ) {
			if ( $this->last_result ) {
				$i = 0;
				foreach( $this->last_result as $row ) {
					$new_array[$i] = (array) $row;
					if ( $output == ARRAY_N ) {
						$new_array[$i] = array_values($new_array[$i]);
					}
					$i++;
				}
				return $new_array;
			} else {
				return null;
			}
		}
	}

	/**
	 * Grabs column metadata from the last query
	 * @param string $info_type one of name, table, def, max_length, not_null, primary_key, multiple_key, unique_key, numeric, blob, type, unsigned, zerofill
	 * @param int $col_offset 0: col name. 1: which table the col's in. 2: col's max length. 3: if the col is numeric. 4: col's type
	 * @return mixed results
	 */
	function get_col_info($info_type = 'name', $col_offset = -1) {
		if ( $this->col_info ) {
			if ( $col_offset == -1 ) {
				$i = 0;
				foreach($this->col_info as $col ) {
					$new_array[$i] = $col->{$info_type};
					$i++;
				}
				return $new_array;
			} else {
				return $this->col_info[$col_offset]->{$info_type};
			}
		}
	}

	/**
	 * Starts the timer, for debugging purposes
	 */
	function timer_start() {
		$mtime = microtime();
		$mtime = explode(' ', $mtime);
		$this->time_start = $mtime[1] + $mtime[0];
		return true;
	}

	/**
	 * Stops the debugging timer
	 * @return int total time spent on the query, in milliseconds
	 */
	function timer_stop() {
		$mtime = microtime();
		$mtime = explode(' ', $mtime);
		$time_end = $mtime[1] + $mtime[0];
		$time_total = $time_end - $this->time_start;
		return $time_total;
	}

	/**
	 * Wraps fatal errors in a nice header and footer and dies.
	 * @param string $message
	 */
	function bail($message) { // Just wraps errors in a nice header and footer
		if ( !$this->show_errors )
			return false;
		wp_die($message);
	}
	/**
	 * Checks wether of not the database version is high enough to support the features WordPress uses
	 * @global $wp_version
	 */
	function check_database_version()
	{
		global $wp_version;
		// Make sure the server has MySQL 4.0
		$mysql_version = preg_replace('|[^0-9\.]|', '', @mysql_get_server_info());
		if ( version_compare($mysql_version, '4.0.0', '<') )
			return new WP_Error('database_version',sprintf(__('<strong>ERROR</strong>: WordPress %s requires MySQL 4.0.0 or higher'), $wp_version));
	}

	/**
	 * This function is called when WordPress is generating the table schema to determine wether or not the current database
	 * supports or needs the collation statements.
	 */
	function supports_collation()
	{
		return ( version_compare(mysql_get_server_info(), '4.1.0', '>=') );
	}
}

if ( ! isset($wpdb) )
	$wpdb = new wpdb(DB_USER, DB_PASSWORD, DB_NAME, DB_HOST);
?>