+/**
+ * Given a meta query, generates SQL clauses to be appended to a main query
+ *
+ * @since 3.2.0
+ *
+ * @see WP_Meta_Query
+ *
+ * @param array $meta_query A meta query
+ * @param string $type Type of meta
+ * @param string $primary_table
+ * @param string $primary_id_column
+ * @param object $context (optional) The main query object
+ * @return array( 'join' => $join_sql, 'where' => $where_sql )
+ */
+function get_meta_sql( $meta_query, $type, $primary_table, $primary_id_column, $context = null ) {
+ $meta_query_obj = new WP_Meta_Query( $meta_query );
+ return $meta_query_obj->get_sql( $type, $primary_table, $primary_id_column, $context );
+}
+
+/**
+ * Container class for a multiple metadata query
+ *
+ * @since 3.2.0
+ */
+class WP_Meta_Query {
+ /**
+ * List of metadata queries. A single query is an associative array:
+ * - 'key' string The meta key
+ * - 'value' string|array The meta value
+ * - 'compare' (optional) string How to compare the key to the value.
+ * Possible values: '=', '!=', '>', '>=', '<', '<=', 'LIKE', 'NOT LIKE', 'IN', 'NOT IN', 'BETWEEN', 'NOT BETWEEN'.
+ * Default: '='
+ * - 'type' string (optional) The type of the value.
+ * Possible values: 'NUMERIC', 'BINARY', 'CHAR', 'DATE', 'DATETIME', 'DECIMAL', 'SIGNED', 'TIME', 'UNSIGNED'.
+ * Default: 'CHAR'
+ *
+ * @since 3.2.0
+ * @access public
+ * @var array
+ */
+ public $queries = array();
+
+ /**
+ * The relation between the queries. Can be one of 'AND' or 'OR'.
+ *
+ * @since 3.2.0
+ * @access public
+ * @var string
+ */
+ public $relation;
+
+ /**
+ * Constructor
+ *
+ * @param array $meta_query (optional) A meta query
+ */
+ function __construct( $meta_query = false ) {
+ if ( !$meta_query )
+ return;
+
+ if ( isset( $meta_query['relation'] ) && strtoupper( $meta_query['relation'] ) == 'OR' ) {
+ $this->relation = 'OR';
+ } else {
+ $this->relation = 'AND';
+ }
+
+ $this->queries = array();
+
+ foreach ( $meta_query as $key => $query ) {
+ if ( ! is_array( $query ) )
+ continue;
+
+ $this->queries[] = $query;
+ }
+ }
+
+ /**
+ * Constructs a meta query based on 'meta_*' query vars
+ *
+ * @since 3.2.0
+ * @access public
+ *
+ * @param array $qv The query variables
+ */
+ function parse_query_vars( $qv ) {
+ $meta_query = array();
+
+ // Simple query needs to be first for orderby=meta_value to work correctly
+ foreach ( array( 'key', 'compare', 'type' ) as $key ) {
+ if ( !empty( $qv[ "meta_$key" ] ) )
+ $meta_query[0][ $key ] = $qv[ "meta_$key" ];
+ }
+
+ // WP_Query sets 'meta_value' = '' by default
+ if ( isset( $qv[ 'meta_value' ] ) && '' !== $qv[ 'meta_value' ] )
+ $meta_query[0]['value'] = $qv[ 'meta_value' ];
+
+ if ( !empty( $qv['meta_query'] ) && is_array( $qv['meta_query'] ) ) {
+ $meta_query = array_merge( $meta_query, $qv['meta_query'] );
+ }
+
+ $this->__construct( $meta_query );
+ }
+
+ /**
+ * Generates SQL clauses to be appended to a main query.
+ *
+ * @since 3.2.0
+ * @access public
+ *
+ * @param string $type Type of meta
+ * @param string $primary_table
+ * @param string $primary_id_column
+ * @param object $context (optional) The main query object
+ * @return array( 'join' => $join_sql, 'where' => $where_sql )
+ */
+ function get_sql( $type, $primary_table, $primary_id_column, $context = null ) {
+ global $wpdb;
+
+ if ( ! $meta_table = _get_meta_table( $type ) )
+ return false;
+
+ $meta_id_column = esc_sql( $type . '_id' );
+
+ $join = array();
+ $where = array();
+
+ foreach ( $this->queries as $k => $q ) {
+ $meta_key = isset( $q['key'] ) ? trim( $q['key'] ) : '';
+ $meta_type = isset( $q['type'] ) ? strtoupper( $q['type'] ) : 'CHAR';
+
+ if ( 'NUMERIC' == $meta_type )
+ $meta_type = 'SIGNED';
+ elseif ( ! in_array( $meta_type, array( 'BINARY', 'CHAR', 'DATE', 'DATETIME', 'DECIMAL', 'SIGNED', 'TIME', 'UNSIGNED' ) ) )
+ $meta_type = 'CHAR';
+
+ $i = count( $join );
+ $alias = $i ? 'mt' . $i : $meta_table;
+
+ // Set JOIN
+ $join[$i] = "INNER JOIN $meta_table";
+ $join[$i] .= $i ? " AS $alias" : '';
+ $join[$i] .= " ON ($primary_table.$primary_id_column = $alias.$meta_id_column)";
+
+ $where[$k] = '';
+ if ( !empty( $meta_key ) )
+ $where[$k] = $wpdb->prepare( "$alias.meta_key = %s", $meta_key );
+
+ if ( !isset( $q['value'] ) ) {
+ if ( empty( $where[$k] ) )
+ unset( $join[$i] );
+ continue;
+ }
+
+ $meta_value = $q['value'];
+
+ $meta_compare = is_array( $meta_value ) ? 'IN' : '=';
+ if ( isset( $q['compare'] ) )
+ $meta_compare = strtoupper( $q['compare'] );
+
+ if ( ! in_array( $meta_compare, array( '=', '!=', '>', '>=', '<', '<=', 'LIKE', 'NOT LIKE', 'IN', 'NOT IN', 'BETWEEN', 'NOT BETWEEN' ) ) )
+ $meta_compare = '=';
+
+ if ( in_array( $meta_compare, array( 'IN', 'NOT IN', 'BETWEEN', 'NOT BETWEEN' ) ) ) {
+ if ( ! is_array( $meta_value ) )
+ $meta_value = preg_split( '/[,\s]+/', $meta_value );
+
+ if ( empty( $meta_value ) ) {
+ unset( $join[$i] );
+ continue;
+ }
+ } else {
+ $meta_value = trim( $meta_value );
+ }
+
+ if ( 'IN' == substr( $meta_compare, -2) ) {
+ $meta_compare_string = '(' . substr( str_repeat( ',%s', count( $meta_value ) ), 1 ) . ')';
+ } elseif ( 'BETWEEN' == substr( $meta_compare, -7) ) {
+ $meta_value = array_slice( $meta_value, 0, 2 );
+ $meta_compare_string = '%s AND %s';
+ } elseif ( 'LIKE' == substr( $meta_compare, -4 ) ) {
+ $meta_value = '%' . like_escape( $meta_value ) . '%';
+ $meta_compare_string = '%s';
+ } else {
+ $meta_compare_string = '%s';
+ }
+
+ if ( ! empty( $where[$k] ) )
+ $where[$k] .= ' AND ';
+
+ $where[$k] = ' (' . $where[$k] . $wpdb->prepare( "CAST($alias.meta_value AS {$meta_type}) {$meta_compare} {$meta_compare_string})", $meta_value );
+ }
+
+ $where = array_filter( $where );
+
+ if ( empty( $where ) )
+ $where = '';
+ else
+ $where = ' AND (' . implode( "\n{$this->relation} ", $where ) . ' )';
+
+ $join = implode( "\n", $join );
+ if ( ! empty( $join ) )
+ $join = ' ' . $join;
+
+ return apply_filters_ref_array( 'get_meta_sql', array( compact( 'join', 'where' ), $this->queries, $type, $primary_table, $primary_id_column, $context ) );
+ }
+}
+