Cricao de Sites - 650 Layouts Prontos/WebMasters.iso/Blogs/wordpress2.6.exe/wordpress2.6/wp-includes/wp-db.php

PHP Script | 2008-07-11 | 23.8 KB | 971 lines

<?php
/**
 * WordPress DB Class
 *
 * Original code from {@link http://php.justinvincent.com Justin Vincent ([e-mail])}
 *
 * @package WordPress
 * @subpackage Database
 * @since 0.71
 */

/**
 * @since 0.71
 */
define('EZSQL_VERSION', 'WP1.25');

/**
 * @since 0.71
 */
define('OBJECT', 'OBJECT', true);

/**
 * @since {@internal Version Unknown}}
 */
define('OBJECT_K', 'OBJECT_K', false);

/**
 * @since 0.71
 */
define('ARRAY_A', 'ARRAY_A', false);

/**
 * @since 0.71
 */
define('ARRAY_N', 'ARRAY_N', false);

/**
 * WordPress Database Access Abstraction Object
 *
 * It is possible to replace this class with your own
 * by setting the $wpdb global variable in wp-content/wpdb.php
 * file with your class. You can name it wpdb also, since
 * this file will not be included, if the other file is
 * available.
 *
 * @link http://codex.wordpress.org/Function_Reference/wpdb_Class
 *
 * @package WordPress
 * @subpackage Database
 * @since 0.71
 * @final
 */
class wpdb {

    /**
     * Whether to show SQL/DB errors
     *
     * @since 0.71
     * @access private
     * @var bool
     */
    var $show_errors = false;

    /**
     * Whether to suppress errors during the DB bootstrapping.
     *
     * @access private
     * @since {@internal Version Unknown}}
     * @var bool
     */
    var $suppress_errors = false;

    /**
     * The last error during query.
     *
     * @since {@internal Version Unknown}}
     * @var string
     */
    var $last_error = '';

    /**
     * Amount of queries made
     *
     * @since 1.2.0
     * @access private
     * @var int
     */
    var $num_queries = 0;

    /**
     * Saved result of the last query made
     *
     * @since 1.2.0
     * @access private
     * @var array
     */
    var $last_query;

    /**
     * Saved info on the table column
     *
     * @since 1.2.0
     * @access private
     * @var array
     */
    var $col_info;

    /**
     * Saved queries that were executed
     *
     * @since 1.5.0
     * @access private
     * @var array
     */
    var $queries;

    /**
     * WordPress table prefix
     *
     * You can set this to have multiple WordPress installations
     * in a single database. The second reason is for possible
     * security precautions.
     *
     * @since 0.71
     * @access private
     * @var string
     */
    var $prefix = '';

    /**
     * Whether the database queries are ready to start executing.
     *
     * @since 2.5.0
     * @access private
     * @var bool
     */
    var $ready = false;

    /**
     * WordPress Posts table
     *
     * @since 1.5.0
     * @access public
     * @var string
     */
    var $posts;

    /**
     * WordPress Users table
     *
     * @since 1.5.0
     * @access public
     * @var string
     */
    var $users;

    /**
     * WordPress Categories table
     *
     * @since 1.5.0
     * @access public
     * @var string
     */
    var $categories;

    /**
     * WordPress Post to Category table
     *
     * @since 1.5.0
     * @access public
     * @var string
     */
    var $post2cat;

    /**
     * WordPress Comments table
     *
     * @since 1.5.0
     * @access public
     * @var string
     */
    var $comments;

    /**
     * WordPress Links table
     *
     * @since 1.5.0
     * @access public
     * @var string
     */
    var $links;

    /**
     * WordPress Options table
     *
     * @since 1.5.0
     * @access public
     * @var string
     */
    var $options;

    /**
     * WordPress Post Metadata table
     *
     * @since {@internal Version Unknown}}
     * @access public
     * @var string
     */
    var $postmeta;

    /**
     * WordPress User Metadata table
     *
     * @since 2.3.0
     * @access public
     * @var string
     */
    var $usermeta;

    /**
     * WordPress Terms table
     *
     * @since 2.3.0
     * @access public
     * @var string
     */
    var $terms;

    /**
     * WordPress Term Taxonomy table
     *
     * @since 2.3.0
     * @access public
     * @var string
     */
    var $term_taxonomy;

    /**
     * WordPress Term Relationships table
     *
     * @since 2.3.0
     * @access public
     * @var string
     */
    var $term_relationships;

    /**
     * List of WordPress tables
     *
     * @since {@internal Version Unknown}}
     * @access private
     * @var array
     */
    var $tables = array('users', 'usermeta', 'posts', 'categories', 'post2cat', 'comments', 'links', 'link2cat', 'options',
            'postmeta', 'terms', 'term_taxonomy', 'term_relationships');

    /**
     * Database table columns charset
     *
     * @since 2.2.0
     * @access public
     * @var string
     */
    var $charset;

    /**
     * Database table columns collate
     *
     * @since 2.2.0
     * @access public
     * @var string
     */
    var $collate;

    /**
     * Connects to the database server and selects a database
     *
     * PHP4 compatibility layer for calling the PHP5 constructor.
     *
     * @uses wpdb::__construct() Passes parameters and returns result
     * @since 0.71
     *
     * @param string $dbuser MySQL database user
     * @param string $dbpassword MySQL database password
     * @param string $dbname MySQL database name
     * @param string $dbhost MySQL database host
     */
    function wpdb($dbuser, $dbpassword, $dbname, $dbhost) {
        return $this->__construct($dbuser, $dbpassword, $dbname, $dbhost);
    }

    /**
     * Connects to the database server and selects a database
     *
     * PHP5 style constructor for compatibility with PHP5. Does
     * the actual setting up of the class properties and connection
     * to the database.
     *
     * @since 2.0.8
     *
     * @param string $dbuser MySQL database user
     * @param string $dbpassword MySQL database password
     * @param string $dbname MySQL database name
     * @param string $dbhost MySQL database host
     */
    function __construct($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(sprintf(/*WP_I18N_DB_CONN_ERROR*/"
<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>%s</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>
"/*/WP_I18N_DB_CONN_ERROR*/, $dbhost));
            return;
        }

        $this->ready = true;

        if ( $this->supports_collation() ) {
            $collation_query = '';
            if ( !empty($this->charset) ) {
                $collation_query = "SET NAMES '{$this->charset}'";
                if (!empty($this->collate) )
                    $collation_query .= " COLLATE '{$this->collate}'";
            }

            if ( !empty($collation_query) )
                $this->query($collation_query);

        }

        $this->select($dbname);
    }

    /**
     * PHP5 style destructor and will run when database object is destroyed.
     *
     * @since 2.0.8
     *
     * @return bool Always true
     */
    function __destruct() {
        return true;
    }

    /**
     * Sets the table prefix for the WordPress tables.
     *
     * Also allows for the CUSTOM_USER_TABLE and CUSTOM_USER_META_TABLE to
     * override the WordPress users and usersmeta tables.
     *
     * @since 2.5.0
     *
     * @param string $prefix Alphanumeric name for the new prefix.
     * @return string Old prefix
     */
    function set_prefix($prefix) {

        if ( preg_match('|[^a-z0-9_]|i', $prefix) )
            return new WP_Error('invalid_db_prefix', /*WP_I18N_DB_BAD_PREFIX*/'Invalid database prefix'/*/WP_I18N_DB_BAD_PREFIX*/);

        $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 database connection.
     *
     * The database name will be changed based on the current database
     * connection. On failure, the execution will bail and display an DB error.
     *
     * @since 0.71
     *
     * @param string $db MySQL database name
     * @return null Always null.
     */
    function select($db) {
        if (!@mysql_select_db($db, $this->dbh)) {
            $this->ready = false;
            $this->bail(sprintf(/*WP_I18N_DB_SELECT_DB*/'
<h1>Can’t select database</h1>
<p>We were able to connect to the database server (which means your username and password is okay) but not able to select the <code>%1$s</code> database.</p>
<ul>
<li>Are you sure it exists?</li>
<li>Does the user <code>%2$s</code> have permission to use the <code>%1$s</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>'/*/WP_I18N_DB_SELECT_DB*/, $db, DB_USER));
            return;
        }
    }

    /**
     * Escapes content for insertion into the database, for security
     *
     * @since 0.71
     *
     * @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
     *
     * @since 2.3.0
     *
     * @param string $s
     */
    function escape_by_ref(&$s) {
        $s = $this->escape($s);
    }

    /**
     * Prepares a SQL query for safe use, using sprintf() syntax.
     *
     * @link http://php.net/sprintf See for syntax to use for query string.
     * @since 2.3.0
     *
     * @param null|string $args If string, first parameter must be query statement
     * @param mixed $args,... If additional parameters, they will be set inserted into the query.
     * @return null|string Sanitized query string
     */
    function prepare($args=null) {
        if ( is_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.
     *
     * @since 0.71
     * @global array $EZSQL_ERROR Stores error information of query and error string
     *
     * @param string $str The error to display
     * @return bool False if the showing of errors is disabled.
     */
    function print_error($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;

        if ( $caller = $this->get_caller() )
            $error_str = sprintf(/*WP_I18N_DB_QUERY_ERROR_FULL*/'WordPress database error %1$s for query %2$s made by %3$s'/*/WP_I18N_DB_QUERY_ERROR_FULL*/, $str, $this->last_query, $caller);
        else
            $error_str = sprintf(/*WP_I18N_DB_QUERY_ERROR*/'WordPress database error %1$s for query %2$s'/*/WP_I18N_DB_QUERY_ERROR*/, $str, $this->last_query);

        $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>";
    }

    /**
     * Enables showing of database errors.
     *
     * This function should be used only to enable showing of errors.
     * wpdb::hide_errors() should be used instead for hiding of errors. However,
     * this function can be used to enable and disable showing of database
     * errors.
     *
     * @since 0.71
     *
     * @param bool $show Whether to show or hide errors
     * @return bool Old value for showing errors.
     */
    function show_errors( $show = true ) {
        $errors = $this->show_errors;
        $this->show_errors = $show;
        return $errors;
    }

    /**
     * Disables showing of database errors.
     *
     * @since 0.71
     *
     * @return bool Whether showing of errors was active or not
     */
    function hide_errors() {
        $show = $this->show_errors;
        $this->show_errors = false;
        return $show;
    }

    /**
     * Whether to suppress database errors.
     *
     * @param unknown_type $suppress
     * @return unknown
     */
    function suppress_errors( $suppress = true ) {
        $errors = $this->suppress_errors;
        $this->suppress_errors = $suppress;
        return $errors;
    }

    /**
     * Kill cached query results.
     *
     * @since 0.71
     */
    function flush() {
        $this->last_result = array();
        $this->col_info = null;
        $this->last_query = null;
    }

    /**
     * Perform a MySQL database query, using current database connection.
     *
     * More information can be found on the codex page.
     *
     * @since 0.71
     *
     * @param string $query
     * @return unknown
     */
    function query($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 ( defined('SAVEQUERIES') && SAVEQUERIES )
            $this->timer_start();

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

        if ( defined('SAVEQUERIES') && 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.
     *
     * @since 2.5.0
     *
     * @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.
     *
     * @since 2.5.0
     *
     * @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 ) );
    }

    /**
     * Retrieve one variable from the database.
     *
     * This combines the functionality of wpdb::get_row() and wpdb::get_col(),
     * so both the column and row can be picked.
     *
     * It is possible to use this function without executing more queries. If
     * you already made a query, you can set the $query to 'null' value and just
     * retrieve either the column and row of the last query result.
     *
     * @since 0.71
     *
     * @param string $query Can be null as well, for caching
     * @param int $x Column num to return
     * @param int $y Row num to return
     * @return mixed Database query results
     */
    function get_var($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;
    }

    /**
     * Retrieve one row from the database.
     *
     * @since 0.71
     *
     * @param string $query SQL query
     * @param string $output ARRAY_A | ARRAY_N | OBJECT
     * @param int $y Row num to return
     * @return mixed Database query results
     */
    function get_row($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(/*WP_I18N_DB_GETROW_ERROR*/" \$db->get_row(string query, output type, int offset) -- Output type must be one of: OBJECT, ARRAY_A, ARRAY_N"/*/WP_I18N_DB_GETROW_ERROR*/);
        }
    }

    /**
     * Retrieve one column from the database.
     *
     * @since 0.71
     *
     * @param string $query Can be null as well, for caching
     * @param int $x Col num to return. Starts from 0.
     * @return array Column results
     */
    function get_col($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;
    }

    /**
     * Retrieve an entire result set from the database.
     *
     * @since 0.71
     *
     * @param string|null $query Can also be null to pull from the cache
     * @param string $output ARRAY_A | ARRAY_N | OBJECT_K | OBJECT
     * @return mixed Database query results
     */
    function get_results($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;
            }
        }
    }

    /**
     * Retrieve column metadata from the last query.
     *
     * @since 0.71
     *
     * @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 $col_offset 0: col name. 1: which table the col's in. 2: col's max length. 3: if the col is numeric. 4: col's type
     * @return mixed Column Results
     */
    function get_col_info($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.
     *
     * @since 1.5.0
     *
     * @return bool Always returns true
     */
    function timer_start() {
        $mtime = microtime();
        $mtime = explode(' ', $mtime);
        $this->time_start = $mtime[1] + $mtime[0];
        return true;
    }

    /**
     * Stops the debugging timer.
     *
     * @since 1.5.0
     *
     * @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.
     *
     * @since 1.5.0
     *
     * @param string $message
     * @return unknown
     */
    function bail($message) {
        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);
    }

    /**
     * Whether or not MySQL database is minimal required version.
     *
     * @since 2.5.0
     * @uses $wp_version
     *
     * @return WP_Error
     */
    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));
    }

    /**
     * Whether of not the database version supports collation.
     *
     * Called when WordPress is generating the table scheme.
     *
     * @since 2.5.0
     *
     * @return bool True if collation is supported, false if version does not
     */
    function supports_collation()
    {
        return ( version_compare(mysql_get_server_info($this->dbh), '4.1.0', '>=') );
    }

    /**
     * Retrieve the name of the function that called wpdb.
     *
     * Requires PHP 4.3 and searches up the list of functions until it reaches
     * the one that would most logically had called this method.
     *
     * @since 2.5.0
     *
     * @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) ) {
    /**
     * WordPress Database Object, if it isn't set already in wp-content/wpdb.php
     * @global object $wpdb Creates a new wpdb object based on wp-config.php Constants for the database
     * @since 0.71
     */
    $wpdb = new wpdb(DB_USER, DB_PASSWORD, DB_NAME, DB_HOST);
}
?>