WordPress at a glance
function is not described

_wp_mysql_week() WP 3.0.0

Return a MySQL expression for selecting the week number based on the start_of_week option.

No Hooks.

Return

String. SQL clause.

Usage

_wp_mysql_week( $column );
$column(string) (required)
Database column.

Code of wp mysql week: wp-includes/functions.php VER 5.0.3

<?php
function _wp_mysql_week( $column ) {
	switch ( $start_of_week = (int) get_option( 'start_of_week' ) ) {
	case 1 :
		return "WEEK( $column, 1 )";
	case 2 :
	case 3 :
	case 4 :
	case 5 :
	case 6 :
		return "WEEK( DATE_SUB( $column, INTERVAL $start_of_week DAY ), 0 )";
	case 0 :
	default :
		return "WEEK( $column, 0 )";
	}
}