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maybe_add_column( string $table_name, string $column_name, string $create_ddl )

Adds column to a database table, if it doesn’t already exist.

Parameters

$table_name

(string) (Required) Database table name.

$column_name

(string) (Required) Table column name.

$create_ddl

(string) (Required) SQL statement to add column.

Return

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

Source

File: wp-admin/includes/upgrade.php 

function maybe_add_column( $table_name, $column_name, $create_ddl ) {
	global $wpdb;

	foreach ( $wpdb->get_col( "DESC $table_name", 0 ) as $column ) {
		if ( $column === $column_name ) {
			return true;
		}
	}

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

	// We cannot directly tell that whether this succeeded!
	foreach ( $wpdb->get_col( "DESC $table_name", 0 ) as $column ) {
		if ( $column === $column_name ) {
			return true;
		}
	}

	return false;
}

Uses

Uses Description
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.

Changelog

Version Description
1.3.0 Introduced.

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