wpdb::select( string $db, resource|null $dbh = null )

Selects a database using the current database connection.


Description

The database name will be changed based on the current database connection. On failure, the execution will bail and display an DB error.


Parameters

$db

(Required) MySQL database name

$dbh

(Optional) link identifier.

Default value: null


Source

File: wp-includes/wp-db.php

	public function select( $db, $dbh = null ) {
		if ( is_null($dbh) )
			$dbh = $this->dbh;

		if ( $this->use_mysqli ) {
			$success = mysqli_select_db( $dbh, $db );
		} else {
			$success = mysql_select_db( $db, $dbh );
		}
		if ( ! $success ) {
			$this->ready = false;
			if ( ! did_action( 'template_redirect' ) ) {
				wp_load_translations_early();

				$message = '<h1>' . __( 'Can&#8217;t select database' ) . "</h1>\n";

				$message .= '<p>' . sprintf(
					/* translators: %s: database name */
					__( 'We were able to connect to the database server (which means your username and password is okay) but not able to select the %s database.' ),
					'<code>' . htmlspecialchars( $db, ENT_QUOTES ) . '</code>'
				) . "</p>\n";

				$message .= "<ul>\n";
				$message .= '<li>' . __( 'Are you sure it exists?' ) . "</li>\n";

				$message .= '<li>' . sprintf(
					/* translators: 1: database user, 2: database name */
					__( 'Does the user %1$s have permission to use the %2$s database?' ),
					'<code>' . htmlspecialchars( $this->dbuser, ENT_QUOTES )  . '</code>',
					'<code>' . htmlspecialchars( $db, ENT_QUOTES ) . '</code>'
				) . "</li>\n";

				$message .= '<li>' . sprintf(
					/* translators: %s: database name */
					__( 'On some systems the name of your database is prefixed with your username, so it would be like <code>username_%1$s</code>. Could that be the problem?' ),
					htmlspecialchars( $db, ENT_QUOTES )
				). "</li>\n";

				$message .= "</ul>\n";

				$message .= '<p>' . sprintf(
					/* translators: %s: support forums URL */
					__( 'If you don&#8217;t know how to set up a database you should <strong>contact your host</strong>. If all else fails you may find help at the <a href="%s">ClassicPress Support Forums</a>.' ),
					__( 'https://forums.classicpress.net/c/support' )
				) . "</p>\n";

				$this->bail( $message, 'db_select_fail' );
			}
		}
	}


Changelog

Changelog
Version Description
WP-0.71 Introduced.