WP_Tax_Query::get_sql_for_query( array $query, int $depth )
Generate SQL clauses for a single query array.
Description
If nested subqueries are found, this method recurses the tree to produce the properly nested SQL.
Parameters
- $query
-
(Required) Query to parse (passed by reference).
- $depth
-
(Optional) Number of tree levels deep we currently are. Used to calculate indentation. Default 0.
Return
(array) Array containing JOIN and WHERE SQL clauses to append to a single query array.
- 'join'
(string) SQL fragment to append to the main JOIN clause. - 'where'
(string) SQL fragment to append to the main WHERE clause.
Source
File: wp-includes/class-wp-tax-query.php
protected function get_sql_for_query( &$query, $depth = 0 ) {
$sql_chunks = array(
'join' => array(),
'where' => array(),
);
$sql = array(
'join' => '',
'where' => '',
);
$indent = '';
for ( $i = 0; $i < $depth; $i++ ) {
$indent .= " ";
}
foreach ( $query as $key => &$clause ) {
if ( 'relation' === $key ) {
$relation = $query['relation'];
} elseif ( is_array( $clause ) ) {
// This is a first-order clause.
if ( $this->is_first_order_clause( $clause ) ) {
$clause_sql = $this->get_sql_for_clause( $clause, $query );
$where_count = count( $clause_sql['where'] );
if ( ! $where_count ) {
$sql_chunks['where'][] = '';
} elseif ( 1 === $where_count ) {
$sql_chunks['where'][] = $clause_sql['where'][0];
} else {
$sql_chunks['where'][] = '( ' . implode( ' AND ', $clause_sql['where'] ) . ' )';
}
$sql_chunks['join'] = array_merge( $sql_chunks['join'], $clause_sql['join'] );
// This is a subquery, so we recurse.
} else {
$clause_sql = $this->get_sql_for_query( $clause, $depth + 1 );
$sql_chunks['where'][] = $clause_sql['where'];
$sql_chunks['join'][] = $clause_sql['join'];
}
}
}
// Filter to remove empties.
$sql_chunks['join'] = array_filter( $sql_chunks['join'] );
$sql_chunks['where'] = array_filter( $sql_chunks['where'] );
if ( empty( $relation ) ) {
$relation = 'AND';
}
// Filter duplicate JOIN clauses and combine into a single string.
if ( ! empty( $sql_chunks['join'] ) ) {
$sql['join'] = implode( ' ', array_unique( $sql_chunks['join'] ) );
}
// Generate a single WHERE clause with proper brackets and indentation.
if ( ! empty( $sql_chunks['where'] ) ) {
$sql['where'] = '( ' . "\n " . $indent . implode( ' ' . "\n " . $indent . $relation . ' ' . "\n " . $indent, $sql_chunks['where'] ) . "\n" . $indent . ')';
}
return $sql;
}
Changelog
Version | Description |
---|---|
WP-4.1.0 | Introduced. |