WP_Meta_Query::get_sql_for_clause() WordPress Method
The WordPress method WP_Meta_Query::get_sql_for_clause() is used to generate the SQL code for a given meta query clause. This can be useful when creating your own custom queries or when troubleshooting existing ones.
WP_Meta_Query::get_sql_for_clause( array $clause, array $parent_query, string $clause_key = '' ) #
Generate SQL JOIN and WHERE clauses for a first-order query clause.
Description
"First-order" means that it’s an array with a ‘key’ or ‘value’.
Parameters
- $clause
(array)(Required)Query clause (passed by reference).
- $parent_query
(array)(Required)Parent query array.
- $clause_key
(string)(Optional) The array key used to name the clause in the original
$meta_query
parameters. If not provided, a key will be generated automatically.Default value: ''
Return
(string[]) Array containing JOIN and WHERE SQL clauses to append to a first-order query.
- 'join'
(string) SQL fragment to append to the main JOIN clause. - 'where'
(string) SQL fragment to append to the main WHERE clause.
Source
File: wp-includes/class-wp-meta-query.php
public function get_sql_for_clause( &$clause, $parent_query, $clause_key = '' ) { global $wpdb; $sql_chunks = array( 'where' => array(), 'join' => array(), ); if ( isset( $clause['compare'] ) ) { $clause['compare'] = strtoupper( $clause['compare'] ); } else { $clause['compare'] = isset( $clause['value'] ) && is_array( $clause['value'] ) ? 'IN' : '='; } $non_numeric_operators = array( '=', '!=', 'LIKE', 'NOT LIKE', 'IN', 'NOT IN', 'EXISTS', 'NOT EXISTS', 'RLIKE', 'REGEXP', 'NOT REGEXP', ); $numeric_operators = array( '>', '>=', '<', '<=', 'BETWEEN', 'NOT BETWEEN', ); if ( ! in_array( $clause['compare'], $non_numeric_operators, true ) && ! in_array( $clause['compare'], $numeric_operators, true ) ) { $clause['compare'] = '='; } if ( isset( $clause['compare_key'] ) ) { $clause['compare_key'] = strtoupper( $clause['compare_key'] ); } else { $clause['compare_key'] = isset( $clause['key'] ) && is_array( $clause['key'] ) ? 'IN' : '='; } if ( ! in_array( $clause['compare_key'], $non_numeric_operators, true ) ) { $clause['compare_key'] = '='; } $meta_compare = $clause['compare']; $meta_compare_key = $clause['compare_key']; // First build the JOIN clause, if one is required. $join = ''; // We prefer to avoid joins if possible. Look for an existing join compatible with this clause. $alias = $this->find_compatible_table_alias( $clause, $parent_query ); if ( false === $alias ) { $i = count( $this->table_aliases ); $alias = $i ? 'mt' . $i : $this->meta_table; // JOIN clauses for NOT EXISTS have their own syntax. if ( 'NOT EXISTS' === $meta_compare ) { $join .= " LEFT JOIN $this->meta_table"; $join .= $i ? " AS $alias" : ''; if ( 'LIKE' === $meta_compare_key ) { $join .= $wpdb->prepare( " ON ( $this->primary_table.$this->primary_id_column = $alias.$this->meta_id_column AND $alias.meta_key LIKE %s )", '%' . $wpdb->esc_like( $clause['key'] ) . '%' ); } else { $join .= $wpdb->prepare( " ON ( $this->primary_table.$this->primary_id_column = $alias.$this->meta_id_column AND $alias.meta_key = %s )", $clause['key'] ); } // All other JOIN clauses. } else { $join .= " INNER JOIN $this->meta_table"; $join .= $i ? " AS $alias" : ''; $join .= " ON ( $this->primary_table.$this->primary_id_column = $alias.$this->meta_id_column )"; } $this->table_aliases[] = $alias; $sql_chunks['join'][] = $join; } // Save the alias to this clause, for future siblings to find. $clause['alias'] = $alias; // Determine the data type. $_meta_type = isset( $clause['type'] ) ? $clause['type'] : ''; $meta_type = $this->get_cast_for_type( $_meta_type ); $clause['cast'] = $meta_type; // Fallback for clause keys is the table alias. Key must be a string. if ( is_int( $clause_key ) || ! $clause_key ) { $clause_key = $clause['alias']; } // Ensure unique clause keys, so none are overwritten. $iterator = 1; $clause_key_base = $clause_key; while ( isset( $this->clauses[ $clause_key ] ) ) { $clause_key = $clause_key_base . '-' . $iterator; $iterator++; } // Store the clause in our flat array. $this->clauses[ $clause_key ] =& $clause; // Next, build the WHERE clause. // meta_key. if ( array_key_exists( 'key', $clause ) ) { if ( 'NOT EXISTS' === $meta_compare ) { $sql_chunks['where'][] = $alias . '.' . $this->meta_id_column . ' IS NULL'; } else { /** * In joined clauses negative operators have to be nested into a * NOT EXISTS clause and flipped, to avoid returning records with * matching post IDs but different meta keys. Here we prepare the * nested clause. */ if ( in_array( $meta_compare_key, array( '!=', 'NOT IN', 'NOT LIKE', 'NOT EXISTS', 'NOT REGEXP' ), true ) ) { // Negative clauses may be reused. $i = count( $this->table_aliases ); $subquery_alias = $i ? 'mt' . $i : $this->meta_table; $this->table_aliases[] = $subquery_alias; $meta_compare_string_start = 'NOT EXISTS ('; $meta_compare_string_start .= "SELECT 1 FROM $wpdb->postmeta $subquery_alias "; $meta_compare_string_start .= "WHERE $subquery_alias.post_ID = $alias.post_ID "; $meta_compare_string_end = 'LIMIT 1'; $meta_compare_string_end .= ')'; } switch ( $meta_compare_key ) { case '=': case 'EXISTS': $where = $wpdb->prepare( "$alias.meta_key = %s", trim( $clause['key'] ) ); // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared break; case 'LIKE': $meta_compare_value = '%' . $wpdb->esc_like( trim( $clause['key'] ) ) . '%'; $where = $wpdb->prepare( "$alias.meta_key LIKE %s", $meta_compare_value ); // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared break; case 'IN': $meta_compare_string = "$alias.meta_key IN (" . substr( str_repeat( ',%s', count( $clause['key'] ) ), 1 ) . ')'; $where = $wpdb->prepare( $meta_compare_string, $clause['key'] ); // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared break; case 'RLIKE': case 'REGEXP': $operator = $meta_compare_key; if ( isset( $clause['type_key'] ) && 'BINARY' === strtoupper( $clause['type_key'] ) ) { $cast = 'BINARY'; } else { $cast = ''; } $where = $wpdb->prepare( "$alias.meta_key $operator $cast %s", trim( $clause['key'] ) ); // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared break; case '!=': case 'NOT EXISTS': $meta_compare_string = $meta_compare_string_start . "AND $subquery_alias.meta_key = %s " . $meta_compare_string_end; $where = $wpdb->prepare( $meta_compare_string, $clause['key'] ); // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared break; case 'NOT LIKE': $meta_compare_string = $meta_compare_string_start . "AND $subquery_alias.meta_key LIKE %s " . $meta_compare_string_end; $meta_compare_value = '%' . $wpdb->esc_like( trim( $clause['key'] ) ) . '%'; $where = $wpdb->prepare( $meta_compare_string, $meta_compare_value ); // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared break; case 'NOT IN': $array_subclause = '(' . substr( str_repeat( ',%s', count( $clause['key'] ) ), 1 ) . ') '; $meta_compare_string = $meta_compare_string_start . "AND $subquery_alias.meta_key IN " . $array_subclause . $meta_compare_string_end; $where = $wpdb->prepare( $meta_compare_string, $clause['key'] ); // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared break; case 'NOT REGEXP': $operator = $meta_compare_key; if ( isset( $clause['type_key'] ) && 'BINARY' === strtoupper( $clause['type_key'] ) ) { $cast = 'BINARY'; } else { $cast = ''; } $meta_compare_string = $meta_compare_string_start . "AND $subquery_alias.meta_key REGEXP $cast %s " . $meta_compare_string_end; $where = $wpdb->prepare( $meta_compare_string, $clause['key'] ); // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared break; } $sql_chunks['where'][] = $where; } } // meta_value. if ( array_key_exists( 'value', $clause ) ) { $meta_value = $clause['value']; if ( in_array( $meta_compare, array( 'IN', 'NOT IN', 'BETWEEN', 'NOT BETWEEN' ), true ) ) { if ( ! is_array( $meta_value ) ) { $meta_value = preg_split( '/[,\s]+/', $meta_value ); } } elseif ( is_string( $meta_value ) ) { $meta_value = trim( $meta_value ); } switch ( $meta_compare ) { case 'IN': case 'NOT IN': $meta_compare_string = '(' . substr( str_repeat( ',%s', count( $meta_value ) ), 1 ) . ')'; $where = $wpdb->prepare( $meta_compare_string, $meta_value ); break; case 'BETWEEN': case 'NOT BETWEEN': $where = $wpdb->prepare( '%s AND %s', $meta_value[0], $meta_value[1] ); break; case 'LIKE': case 'NOT LIKE': $meta_value = '%' . $wpdb->esc_like( $meta_value ) . '%'; $where = $wpdb->prepare( '%s', $meta_value ); break; // EXISTS with a value is interpreted as '='. case 'EXISTS': $meta_compare = '='; $where = $wpdb->prepare( '%s', $meta_value ); break; // 'value' is ignored for NOT EXISTS. case 'NOT EXISTS': $where = ''; break; default: $where = $wpdb->prepare( '%s', $meta_value ); break; } if ( $where ) { if ( 'CHAR' === $meta_type ) { $sql_chunks['where'][] = "$alias.meta_value {$meta_compare} {$where}"; } else { $sql_chunks['where'][] = "CAST($alias.meta_value AS {$meta_type}) {$meta_compare} {$where}"; } } } /* * Multiple WHERE clauses (for meta_key and meta_value) should * be joined in parentheses. */ if ( 1 < count( $sql_chunks['where'] ) ) { $sql_chunks['where'] = array( '( ' . implode( ' AND ', $sql_chunks['where'] ) . ' )' ); } return $sql_chunks; }
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Changelog
Version | Description |
---|---|
4.1.0 | Introduced. |