From 27d0a177f730916c3117629486e9dfd330c6c605 Mon Sep 17 00:00:00 2001
From: scribu <scribu@1a063a9b-81f0-0310-95a4-ce76da25c4cd>
Date: Sun, 5 Sep 2010 13:31:33 +0000
Subject: [PATCH] introduce _wp_meta_sql(). Preparation for adding blog_id to
 WP_User_Query. See #14572

git-svn-id: http://svn.automattic.com/wordpress/trunk@15565 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/functions.php | 50 +++++++++++++++++++++++++++++++++++++++
 wp-includes/user.php      | 37 ++++++++++++++++-------------
 2 files changed, 71 insertions(+), 16 deletions(-)

diff --git a/wp-includes/functions.php b/wp-includes/functions.php
index 28f501f038..51dc9ba951 100644
--- a/wp-includes/functions.php
+++ b/wp-includes/functions.php
@@ -4218,6 +4218,56 @@ function _wp_search_sql($string, $cols) {
 	return ' AND (' . implode(' OR ', $searches) . ')';
 }
 
+/*
+ * Used internally to generate an SQL string for searching across multiple meta key = value pairs
+ *
+ * @access private
+ * @since 3.1.0
+ *
+ * @param array $queries An array of queries
+ * @return string
+ */
+function _wp_meta_sql( $queries, $meta_id_column, $table ) {
+	global $wpdb;
+
+	$clauses = array();
+
+	foreach ( $queries as $query ) {
+		$meta_key = trim( @$query['meta_key'] );
+		$meta_value = trim( @$query['meta_value'] );
+		$meta_compare = @$query['meta_compare'];
+
+		if ( empty( $meta_compare ) || !in_array( $meta_compare, array( '=', '!=', '>', '>=', '<', '<=', 'like' ) ) )
+			$meta_compare = '=';
+
+		if ( empty( $meta_key ) )
+			continue;
+
+		$clause = $wpdb->prepare( "WHEN %s THEN meta_value ", $meta_key );
+
+		if ( empty( $meta_value ) ) {
+			$clauses[] = $clause . "IS NOT NULL";
+		} elseif ( 'like' == $meta_compare ) {
+			$clauses[] = $clause . $wpdb->prepare( "LIKE %s", '%' . like_escape( $meta_value ) . '%' );
+		} else {
+			$clauses[] = $clause . $wpdb->prepare( "$meta_compare %s", $meta_value );
+		}
+	}
+
+	if ( empty( $clauses ) )
+		return '';
+
+	return "
+		SELECT $meta_id_column 
+		FROM $table 
+		WHERE CASE meta_key 
+		" . implode( "\n", $clauses ) . "
+		END
+		GROUP BY $meta_id_column
+		HAVING COUNT(*) = " . count( $clauses );
+}
+
+
 /*
  * Used internally to tidy up the search terms
  *
diff --git a/wp-includes/user.php b/wp-includes/user.php
index 0a8355cf30..5f37bb644f 100644
--- a/wp-includes/user.php
+++ b/wp-includes/user.php
@@ -379,7 +379,7 @@ class WP_User_Query {
 				'orderby' => 'login', 'order' => 'ASC',
 				'meta_key' => '', 'meta_value' => '',
 				'include' => array(), 'exclude' => array(),
-				'fields' => 'all'
+				'fields' => 'all',
 			) );
 
 			$this->prepare_query();
@@ -445,26 +445,31 @@ class WP_User_Query {
 
 		$role = trim( $qv['role'] );
 
-		if ( $role || is_multisite() ) {
-			$this->query_from .= " INNER JOIN $wpdb->usermeta ON $wpdb->users.ID = $wpdb->usermeta.user_id";
-			$this->query_where .= $wpdb->prepare( " AND $wpdb->usermeta.meta_key = %s", $wpdb->prefix . 'capabilities' );
-		}
+		$meta_queries = array();
+
+		$cap_meta_query = array();
+		$cap_meta_key = $wpdb->prefix . 'capabilities';
+
+		if ( $role || is_multisite() )
+			$cap_meta_query['meta_key'] = $cap_meta_key;
 
 		if ( $role ) {
-			$this->query_where .= $wpdb->prepare( " AND $wpdb->usermeta.meta_value LIKE %s", '%' . like_escape( $role ) . '%' );
+			$cap_meta_query['meta_value'] = $role;
+			$cap_meta_query['meta_compare'] = 'like';
 		}
 
-		$meta_key = trim( $qv['meta_key'] );
-		$meta_value = trim( $qv['meta_value'] );
-		if ( $meta_key ) {
-			if ( empty( $meta_value ) ) {
-				$subquery = $wpdb->prepare( "SELECT user_id FROM {$wpdb->usermeta} WHERE meta_key = %s", $meta_key );
-			}
-			else {
-				$subquery = $wpdb->prepare( "SELECT user_id FROM {$wpdb->usermeta} WHERE meta_key = %s AND meta_value = %s", $meta_key, $meta_value );
-			}
+		$meta_queries[] = $cap_meta_query;
 
-			$this->query_where .= " AND $wpdb->users.ID IN ($subquery)";
+		$meta_queries[] = array(
+			'meta_key' => @$qv['meta_key'],
+			'meta_value' => @$qv['meta_key'],
+			'meta_compare' => @$qv['meta_key'],
+		);
+
+		$meta_query_sql = _wp_meta_sql( $meta_queries, 'user_id', $wpdb->usermeta );
+
+		if ( !empty( $meta_query_sql ) ) {
+			$this->query_where .= " AND $wpdb->users.ID IN ($meta_query_sql)";
 		}
 
 		if ( !empty($qv['include']) ) {