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('OBJECT_K', 'OBJECT_K', false);
define('ARRAY_A', 'ARRAY_A', false);
define('ARRAY_N', 'ARRAY_N', false);

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

class wpdb {

	var $show_errors = false;
	var $suppress_errors = false;
	var $last_error = '';
	var $num_queries = 0;
	var $last_query;
	var $col_info;
	var $queries;
	var $prefix = '';
	var $ready = false;

	// Our tables
	var $posts;
	var $users;
	var $categories;
	var $post2cat;
	var $comments;
	var $links;
	var $options;
	var $postmeta;
	var $usermeta;
	var $terms;
	var $term_taxonomy;
	var $term_relationships;
	var $tables = array('users', 'usermeta', 'posts', 'categories', 'post2cat', 'comments', 'links', 'link2cat', 'options',
			'postmeta', 'terms', 'term_taxonomy', '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('WP_DEBUG') and WP_DEBUG == true )
			$this->show_errors();

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

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

		$this->dbh = @mysql_connect($dbhost, $dbuser, $dbpassword, true);
		if (!$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>
");
			return;
		}

		$this->ready = true;

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

		$this->select($dbname);
	}

	function __destruct() {
		return true;
	}

	function set_prefix($prefix) {

		if ( preg_match('|[^a-z0-9_]|i', $prefix) )
			return new WP_Error('invalid_db_prefix', 'Invalid database prefix'); // No gettext here

		$old_prefix = $this->prefix;
		$this->prefix = $prefix;

		foreach ( $this->tables as $table )
			$this->$table = $this->prefix . $table;

		if ( defined('CUSTOM_USER_TABLE') )
			$this->users = CUSTOM_USER_TABLE;

		if ( defined('CUSTOM_USER_META_TABLE') )
			$this->usermeta = CUSTOM_USER_META_TABLE;

		return $old_prefix;
	}

	/**
	 * 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->ready = false;
			$this->bail("
<h1>Can&#8217;t select database</h1>
<p>We were able to connect to the database server (which means your username and password is okay) but not able to select the <code>$db</code> database.</p>
<ul>
<li>Are you sure it exists?</li>
<li>Does the user <code>".DB_USER."</code> have permission to use the <code>$db</code> database?</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>");
			return;
		}
	}

	/**
	 * 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);

		if ( $this->suppress_errors )
			return false;

		$error_str = "WordPress database error $str for query $this->last_query";
		if ( $caller = $this->get_caller() )
			$error_str .= " made by $caller";

		$log_error = true;
		if ( ! function_exists('error_log') )
			$log_error = false;

		$log_file = @ini_get('error_log');
		if ( !empty($log_file) && ('syslog' != $log_file) && !is_writable($log_file) )
			$log_error = false;

		if ( $log_error )
			@error_log($error_str, 0);

		// Is error output turned on or not..
		if ( !$this->show_errors )
			return false;

		$str = htmlspecialchars($str, ENT_QUOTES);
		$query = htmlspecialchars($this->last_query, ENT_QUOTES);

		// 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>";
	}

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

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

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

	function suppress_errors( $suppress = true ) {
		$errors = $this->suppress_errors;
		$this->suppress_errors = $suppress;
		return $errors;
	}

	// ==================================================================
	//	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) {
		if ( ! $this->ready )
			return false;

		// 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(), $this->get_caller() );

		// If there is an error then take note of it..
		if ( $this->last_error = mysql_error($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;
	}

	/**
	 * Insert an array of data into a table
	 * @param string $table WARNING: not sanitized!
	 * @param array $data should not already be SQL-escaped
	 * @return mixed results of $this->query()
	 */
	function insert($table, $data) {
		$data = add_magic_quotes($data);
		$fields = array_keys($data);
		return $this->query("INSERT INTO $table (`" . implode('`,`',$fields) . "`) VALUES ('".implode("','",$data)."')");
	}

	/**
	 * Update a row in the table with an array of data
	 * @param string $table WARNING: not sanitized!
	 * @param array $data should not already be SQL-escaped
	 * @param array $where a named array of WHERE column => value relationships.  Multiple member pairs will be joined with ANDs.  WARNING: the column names are not currently sanitized!
	 * @return mixed results of $this->query()
	 */
	function update($table, $data, $where){
		$data = add_magic_quotes($data);
		$bits = $wheres = array();
		foreach ( array_keys($data) as $k )
			$bits[] = "`$k` = '$data[$k]'";

		if ( is_array( $where ) )
			foreach ( $where as $c => $v )
				$wheres[] = "$c = '" . $this->escape( $v ) . "'";
		else
			return false;
		return $this->query( "UPDATE $table SET " . implode( ', ', $bits ) . ' WHERE ' . implode( ' AND ', $wheres ) . ' LIMIT 1' );
	}

	/**
	 * 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 ( !empty( $this->last_result[$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 $output ARRAY_A | ARRAY_N | OBJECT_K | OBJECT
	 * @return mixed results
	 */
	function get_results($query = null, $output = OBJECT) {
		$this->func_call = "\$db->get_results(\"$query\", $output)";

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

		if ( $output == OBJECT ) {
			// Return an integer-keyed array of row objects
			return $this->last_result;
		} elseif ( $output == OBJECT_K ) {
			// Return an array of row objects with keys from column 1
			// (Duplicates are discarded)
			foreach ( $this->last_result as $row ) {
				$key = array_shift( get_object_vars( $row ) );
				if ( !isset( $new_array[ $key ] ) )
					$new_array[ $key ] = $row;
			}
			return $new_array;
		} elseif ( $output == ARRAY_A || $output == ARRAY_N ) {
			// Return an integer-keyed array of...
			if ( $this->last_result ) {
				$i = 0;
				foreach( $this->last_result as $row ) {
					if ( $output == ARRAY_N ) {
						// ...integer-keyed row arrays
						$new_array[$i] = array_values( get_object_vars( $row ) );
					} else {
						// ...column name-keyed row arrays
						$new_array[$i] = get_object_vars( $row );
					}
					++$i;
				}
				return $new_array;
			}
		}
	}

	/**
	 * 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 ) {
			if ( class_exists('WP_Error') )
				$this->error = new WP_Error('500', $message);
			else
				$this->error = $message;
			return false;
		}
		wp_die($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
		$mysql_version = preg_replace('|[^0-9\.]|', '', @mysql_get_server_info($this->dbh));
		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($this->dbh), '4.1.0', '>=') );
	}

	/**
	 * Get the name of the function that called wpdb.
	 * @return string the name of the calling function
	 */
	function get_caller() {
		// requires PHP 4.3+
		if ( !is_callable('debug_backtrace') )
			return '';

		$bt = debug_backtrace();
		$caller = '';

		foreach ( $bt as $trace ) {
			if ( @$trace['class'] == __CLASS__ )
				continue;
			elseif ( strtolower(@$trace['function']) == 'call_user_func_array' )
				continue;
			elseif ( strtolower(@$trace['function']) == 'apply_filters' )
				continue;
			elseif ( strtolower(@$trace['function']) == 'do_action' )
				continue;

			$caller = $trace['function'];
			break;
		}
		return $caller;
	}

}

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