source: tags/1.5.1.3/wp-includes/wp-db.php @ 2598

<?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 $linkcategories;
        var $options;
        var $optiontypes;
        var $optionvalues;
        var $optiongroups;
        var $optiongroup_options;
        var $postmeta;

        // ==================================================================
        //      DB Constructor - connects to the server and selects a database

        function wpdb($dbuser, $dbpassword, $dbname, $dbhost) {
                $this->dbh = @mysql_connect($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>
");
                }

                $this->select($dbname);
        }

        // ==================================================================
        //      Select a DB (if another one needs to be selected)

        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>");
                }
        }

        // ====================================================================
        //      Format a string correctly for safe insert under all PHP conditions
        
        function escape($str) {
                return addslashes($str);                                
        }

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

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

                // 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>$this->last_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 = null;
                $this->col_info = null;
                $this->last_query = null;
        }

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

        function 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->print_error();
                        return false;
                }

                if ( preg_match("/^\\s*(insert|delete|update|replace) /i",$query) ) {
                        $this->rows_affected = mysql_affected_rows();
                        // Take note of the insert_id
                        if ( preg_match("/^\\s*(insert|replace) /i",$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 DB - see docs for more detail

        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 DB - see docs for more detail

        function get_row($query = null, $output = OBJECT, $y = 0) {
                $this->func_call = "\$db->get_row(\"$query\",$output,$y)";
                if ( $query )
                        $this->query($query);

                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");
                }
        }

        // ==================================================================
        //      Function to get 1 column from the cached result set based in X index
        // se docs for usage and info

        function get_col($query = null , $x = 0) {
                if ( $query )
                        $this->query($query);

                // 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 the the query as a result set - see docs for more details

        function get_results($query = null, $output = OBJECT) {
                $this->func_call = "\$db->get_results(\"$query\", $output)";

                if ( $query )
                        $this->query($query);

                // 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;
                        }
                }
        }


        // ==================================================================
        // Function to get column meta data info pertaining to the last query
        // see docs for more info and usage

        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};
                        }
                }
        }

        function timer_start() {
                $mtime = microtime();
                $mtime = explode(' ', $mtime);
                $this->time_start = $mtime[1] + $mtime[0];
                return true;
        }
        
        function timer_stop($precision = 3) {
                $mtime = microtime();
                $mtime = explode(' ', $mtime);
                $time_end = $mtime[1] + $mtime[0];
                $time_total = $time_end - $this->time_start;
                return $time_total;
        }

        function bail($message) { // Just wraps errors in a nice header and footer
        if ( !$this->show_errors )
                return false;
        header( 'Content-Type: text/html; charset=utf-8');              
        echo <<<HEAD
        <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
        <html xmlns="http://www.w3.org/1999/xhtml">
        <head>
                <title>WordPress &rsaquo; Error</title>
                <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
                <style media="screen" type="text/css">
                <!--
                html {
                        background: #eee;
                }
                body {
                        background: #fff;
                        color: #000;
                        font-family: Georgia, "Times New Roman", Times, serif;
                        margin-left: 25%;
                        margin-right: 25%;
                        padding: .2em 2em;
                }
                
                h1 {
                        color: #006;
                        font-size: 18px;
                        font-weight: lighter;
                }
                
                h2 {
                        font-size: 16px;
                }
                
                p, li, dt {
                        line-height: 140%;
                        padding-bottom: 2px;
                }
        
                ul, ol {
                        padding: 5px 5px 5px 20px;
                }
                #logo {
                        margin-bottom: 2em;
                }
                -->
                </style>
        </head>
        <body>
        <h1 id="logo"><img alt="WordPress" src="http://static.wordpress.org/logo.png" /></h1>
HEAD;
        echo $message;
        echo "</body></html>";
        die();
        }
}

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