WordPress at a glance
filter is not described

posts_join filter-hook . WP 1.5.0

Filters the JOIN clause of the query.


add_filter( 'posts_join', 'filter_function_name_6636', 10, 2 );
function filter_function_name_6636( $join, $this ){
	// filter...

	return $join;
The JOIN clause of the query.
The WP_Query instance (passed by reference).

Where the hook is called

wp-includes/class-wp-query.php 2386
$join = apply_filters_ref_array( 'posts_join', array( $join, &$this ) );

Where the hook is used (in WP core)

Does not used.