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maybe_create_table( string $table_name, string $create_ddl )

Creates a table in the database, if it doesn’t already exist.

Description

This method checks for an existing database and creates a new one if it’s not already present. It doesn’t rely on MySQL’s "IF NOT EXISTS" statement, but chooses to query all tables first and then run the SQL statement creating the table.

Parameters

$table_name

(string) (Required) Database table name.

$create_ddl

(string) (Required) SQL statement to create table.

Return

(bool) True on success or if the table already exists. False on failure.

Source

File: wp-admin/includes/upgrade.php 

function maybe_create_table( $table_name, $create_ddl ) {
	global $wpdb;

	$query = $wpdb->prepare( 'SHOW TABLES LIKE %s', $wpdb->esc_like( $table_name ) );

	if ( $wpdb->get_var( $query ) === $table_name ) {
		return true;
	}

	// Didn't find it, so try to create it.
	$wpdb->query( $create_ddl );

	// We cannot directly tell that whether this succeeded!
	if ( $wpdb->get_var( $query ) === $table_name ) {
		return true;
	}

	return false;
}

Uses

Uses Description
wp-includes/wp-db.php: wpdb::esc_like()

First half of escaping for LIKE special characters % and _ before preparing for MySQL.
wp-includes/wp-db.php: wpdb::get_col()

Retrieves one column from the database.
wp-includes/wp-db.php: wpdb::query()

Performs a MySQL database query, using current database connection.
wp-includes/wp-db.php: wpdb::get_var()

Retrieves one variable from the database.
wp-includes/wp-db.php: wpdb::prepare()

Prepares a SQL query for safe execution.

Changelog

Version Description
1.0.0 Introduced.

© 2003–2019 WordPress Foundation
Licensed under the GNU GPLv2+ License.
https://developer.wordpress.org/reference/functions/maybe_create_table