validate_column example

// Support for passing time-based keys in the top level of the $date_query array.         if ( ! isset( $date_query[0] ) ) {
            $date_query = array( $date_query );
        }

        if ( ! empty( $date_query['column'] ) ) {
            $date_query['column'] = esc_sql( $date_query['column'] );
        } else {
            $date_query['column'] = esc_sql( $default_column );
        }

        $this->column = $this->validate_column( $this->column );

        $this->compare = $this->get_compare( $date_query );

        $this->queries = $this->sanitize_query( $date_query );
    }

    /** * Recursive-friendly query sanitizer. * * Ensures that each query-level clause has a 'relation' key, and that * each first-order clause contains all the necessary keys from `$defaults`. * * @since 4.1.0 * * @param array $queries * @param array $parent_query * @return array Sanitized queries. */