}
/**
- * Ensures a string is a valid SQL order by clause.
+ * Ensures a string is a valid SQL 'order by' clause.
*
- * Accepts one or more columns, with or without ASC/DESC, and also accepts
- * RAND().
+ * Accepts one or more columns, with or without a sort order (ASC / DESC).
+ * e.g. 'column_1', 'column_1, column_2', 'column_1 ASC, column_2 DESC' etc.
+ *
+ * Also accepts 'RAND()'.
*
* @since 2.5.1
*
- * @param string $orderby Order by string to be checked.
- * @return false|string Returns the order by clause if it is a match, false otherwise.
+ * @param string $orderby Order by clause to be validated.
+ * @return string|bool Returns $orderby if valid, false otherwise.
*/
-function sanitize_sql_orderby( $orderby ){
- preg_match('/^\s*([a-z0-9_]+(\s+(ASC|DESC))?(\s*,\s*|\s*$))+|^\s*RAND\(\s*\)\s*$/i', $orderby, $obmatches);
- if ( !$obmatches )
- return false;
- return $orderby;
+function sanitize_sql_orderby( $orderby ) {
+ if ( preg_match( '/^\s*(([a-z0-9_]+|`[a-z0-9_]+`)(\s+(ASC|DESC))?\s*(,\s*(?=[a-z0-9_`])|$))+$/i', $orderby ) || preg_match( '/^\s*RAND\(\s*\)\s*$/i', $orderby ) ) {
+ return $orderby;
+ }
+ return false;
}
/**