Ticket #37699: 37699-query.diff

src/wp-includes/query.php

@@ -1321 +1321 @@
         private $compat_methods = array( 'init_query_flags', 'parse_tax_query' );
 
         /**
+         * @since 4.7.0
+         * @access protected
+         * @var wpdb
+         */
+        protected $db;
+
+        /**
          * Resets query flags to false.
          *
          * The query flags are what page info WordPress was able to figure out.
@@ -2114 +2121 @@
          *
          * @since 3.7.0
          *
-         * @global wpdb $wpdb WordPress database abstraction object.
-         *
          * @param array $q Query variables.
          * @return string WHERE clause.
          */
         protected function parse_search( &$q ) {
-                global $wpdb;
-
                 $search = '';
 
                 // added slashes screw with quote grouping when done early, so done later
@@ -2161 +2164 @@
                         }
 
                         if ( $n && $include ) {
-                                $like = '%' . $wpdb->esc_like( $term ) . '%';
-                                $q['search_orderby_title'][] = $wpdb->prepare( "$wpdb->posts.post_title LIKE %s", $like );
+                                $like = '%' . $this->db->esc_like( $term ) . '%';
+                                $q['search_orderby_title'][] = $this->db->prepare( "{$this->db->posts}.post_title LIKE %s", $like );
                         }
 
-                        $like = $n . $wpdb->esc_like( $term ) . $n;
-                        $search .= $wpdb->prepare( "{$searchand}(($wpdb->posts.post_title $like_op %s) $andor_op ($wpdb->posts.post_excerpt $like_op %s) $andor_op ($wpdb->posts.post_content $like_op %s))", $like, $like, $like );
+                        $like = $n . $this->db->esc_like( $term ) . $n;
+                        $search .= $this->db->prepare( "{$searchand}(({$this->db->posts}.post_title $like_op %s) $andor_op ({$this->db->posts}.post_excerpt $like_op %s) $andor_op ($this->db->posts.post_content $like_op %s))", $like, $like, $like );
                         $searchand = ' AND ';
                 }
 
@@ -2173 +2176 @@
                 if ( ! empty( $search ) ) {
                         $search = " AND ({$search}) ";
                         if ( ! is_user_logged_in() )
-                                $search .= " AND ($wpdb->posts.post_password = '') ";
+                                $search .= " AND ({$this->db->posts}.post_password = '') ";
                 }
 
                 return $search;
@@ -2256 +2259 @@
         /**
          * Generate SQL for the ORDER BY condition based on passed search terms.
          *
-         * @global wpdb $wpdb WordPress database abstraction object.
-         *
          * @param array $q Query variables.
          * @return string ORDER BY clause.
          */
         protected function parse_search_order( &$q ) {
-                global $wpdb;
-
                 if ( $q['search_terms_count'] > 1 ) {
                         $num_terms = count( $q['search_orderby_title'] );
 
@@ -2270 +2269 @@
                         // If the search terms contain negative queries, don't bother ordering by sentence matches.
                         $like = '';
                         if ( ! preg_match( '/(?:\s|^)\-/', $q['s'] ) ) {
-                                $like = '%' . $wpdb->esc_like( $q['s'] ) . '%';
+                                $like = '%' . $this->db->esc_like( $q['s'] ) . '%';
                         }
 
                         $search_orderby = '';
@@ -2277 +2276 @@
 
                         // sentence match in 'post_title'
                         if ( $like ) {
-                                $search_orderby .= $wpdb->prepare( "WHEN $wpdb->posts.post_title LIKE %s THEN 1 ", $like );
+                                $search_orderby .= $this->db->prepare( "WHEN {$this->db->posts}.post_title LIKE %s THEN 1 ", $like );
                         }
 
                         // sanity limit, sort as sentence when more than 6 terms
@@ -2292 +2291 @@
 
                         // Sentence match in 'post_content' and 'post_excerpt'.
                         if ( $like ) {
-                                $search_orderby .= $wpdb->prepare( "WHEN $wpdb->posts.post_excerpt LIKE %s THEN 4 ", $like );
-                                $search_orderby .= $wpdb->prepare( "WHEN $wpdb->posts.post_content LIKE %s THEN 5 ", $like );
+                                $search_orderby .= $this->db->prepare( "WHEN {$this->db->posts}.post_excerpt LIKE %s THEN 4 ", $like );
+                                $search_orderby .= $this->db->prepare( "WHEN {$this->db->posts}.post_content LIKE %s THEN 5 ", $like );
                         }
 
                         if ( $search_orderby ) {
@@ -2314 +2313 @@
          * @since 4.0.0
          * @access protected
          *
-         * @global wpdb $wpdb WordPress database abstraction object.
-         *
          * @param string $orderby Alias for the field to order by.
          * @return string|false Table-prefixed value to used in the ORDER clause. False otherwise.
          */
         protected function parse_orderby( $orderby ) {
-                global $wpdb;
-
                 // Used to filter values.
                 $allowed_keys = array(
                         'post_name', 'post_author', 'post_date', 'post_title', 'post_modified',
@@ -2368 +2363 @@
                         case 'ID':
                         case 'menu_order':
                         case 'comment_count':
-                                $orderby_clause = "$wpdb->posts.{$orderby}";
+                                $orderby_clause = "{$this->db->posts}.{$orderby}";
                                 break;
                         case 'rand':
                                 $orderby_clause = 'RAND()';
@@ -2393 +2388 @@
                                         $orderby_clause = $orderby;
                                 } else {
                                         // Default: order by post field.
-                                        $orderby_clause = "$wpdb->posts.post_" . sanitize_key( $orderby );
+                                        $orderby_clause = "{$this->db->posts}.post_" . sanitize_key( $orderby );
                                 }
 
                                 break;
@@ -2480 +2475 @@
          * @since 1.5.0
          * @access public
          *
-         * @global wpdb $wpdb WordPress database abstraction object.
-         *
          * @return array List of posts.
          */
         public function get_posts() {
-                global $wpdb;
-
                 $this->parse_query();
 
                 /**
@@ -2622 +2613 @@
 
                 switch ( $q['fields'] ) {
                         case 'ids':
-                                $fields = "$wpdb->posts.ID";
+                                $fields = "{$this->db->posts}.ID";
                                 break;
                         case 'id=>parent':
-                                $fields = "$wpdb->posts.ID, $wpdb->posts.post_parent";
+                                $fields = "{$this->db->posts}.ID, {$this->db->posts}.post_parent";
                                 break;
                         default:
-                                $fields = "$wpdb->posts.*";
+                                $fields = "{$this->db->posts}.*";
                 }
 
                 if ( '' !== $q['menu_order'] )
-                        $where .= " AND $wpdb->posts.menu_order = " . $q['menu_order'];
+                        $where .= " AND {$this->db->posts}.menu_order = " . $q['menu_order'];
 
                 // The "m" parameter is meant for months but accepts datetimes of varying specificity
                 if ( $q['m'] ) {
-                        $where .= " AND YEAR($wpdb->posts.post_date)=" . substr($q['m'], 0, 4);
+                        $where .= " AND YEAR({$this->db->posts}.post_date)=" . substr($q['m'], 0, 4);
                         if ( strlen($q['m']) > 5 )
-                                $where .= " AND MONTH($wpdb->posts.post_date)=" . substr($q['m'], 4, 2);
+                                $where .= " AND MONTH({$this->db->posts}.post_date)=" . substr($q['m'], 4, 2);
                         if ( strlen($q['m']) > 7 )
-                                $where .= " AND DAYOFMONTH($wpdb->posts.post_date)=" . substr($q['m'], 6, 2);
+                                $where .= " AND DAYOFMONTH({$this->db->posts}.post_date)=" . substr($q['m'], 6, 2);
                         if ( strlen($q['m']) > 9 )
-                                $where .= " AND HOUR($wpdb->posts.post_date)=" . substr($q['m'], 8, 2);
+                                $where .= " AND HOUR({$this->db->posts}.post_date)=" . substr($q['m'], 8, 2);
                         if ( strlen($q['m']) > 11 )
-                                $where .= " AND MINUTE($wpdb->posts.post_date)=" . substr($q['m'], 10, 2);
+                                $where .= " AND MINUTE({$this->db->posts}.post_date)=" . substr($q['m'], 10, 2);
                         if ( strlen($q['m']) > 13 )
-                                $where .= " AND SECOND($wpdb->posts.post_date)=" . substr($q['m'], 12, 2);
+                                $where .= " AND SECOND({$this->db->posts}.post_date)=" . substr($q['m'], 12, 2);
                 }
 
                 // Handle the other individual date parameters
@@ -2709 +2700 @@
                 }
 
                 if ( '' !== $q['title'] ) {
-                        $where .= $wpdb->prepare( " AND $wpdb->posts.post_title = %s", stripslashes( $q['title'] ) );
+                        $where .= $this->db->prepare( " AND {$this->db->posts}.post_title = %s", stripslashes( $q['title'] ) );
                 }
 
                 // Parameters related to 'post_name'.
                 if ( '' != $q['name'] ) {
                         $q['name'] = sanitize_title_for_query( $q['name'] );
-                        $where .= " AND $wpdb->posts.post_name = '" . $q['name'] . "'";
+                        $where .= " AND {$this->db->posts}.post_name = '" . $q['name'] . "'";
                 } elseif ( '' != $q['pagename'] ) {
                         if ( isset($this->queried_object_id) ) {
                                 $reqpage = $this->queried_object_id;
@@ -2744 +2735 @@
                         if  ( ('page' != get_option('show_on_front') ) || empty($page_for_posts) || ( $reqpage != $page_for_posts ) ) {
                                 $q['pagename'] = sanitize_title_for_query( wp_basename( $q['pagename'] ) );
                                 $q['name'] = $q['pagename'];
-                                $where .= " AND ($wpdb->posts.ID = '$reqpage')";
+                                $where .= " AND ({$this->db->posts}.ID = '$reqpage')";
                                 $reqpage_obj = get_post( $reqpage );
                                 if ( is_object($reqpage_obj) && 'attachment' == $reqpage_obj->post_type ) {
                                         $this->is_attachment = true;
@@ -2756 +2747 @@
                 } elseif ( '' != $q['attachment'] ) {
                         $q['attachment'] = sanitize_title_for_query( wp_basename( $q['attachment'] ) );
                         $q['name'] = $q['attachment'];
-                        $where .= " AND $wpdb->posts.post_name = '" . $q['attachment'] . "'";
+                        $where .= " AND {$this->db->posts}.post_name = '" . $q['attachment'] . "'";
                 } elseif ( is_array( $q['post_name__in'] ) && ! empty( $q['post_name__in'] ) ) {
                         $q['post_name__in'] = array_map( 'sanitize_title_for_query', $q['post_name__in'] );
                         $post_name__in = "'" . implode( "','", $q['post_name__in'] ) . "'";
-                        $where .= " AND $wpdb->posts.post_name IN ($post_name__in)";
+                        $where .= " AND {$this->db->posts}.post_name IN ($post_name__in)";
                 }
 
                 // If an attachment is requested by number, let it supersede any post number.
@@ -2769 +2760 @@
 
                 // If a post number is specified, load that post
                 if ( $q['p'] ) {
-                        $where .= " AND {$wpdb->posts}.ID = " . $q['p'];
+                        $where .= " AND {$this->db->posts}.ID = " . $q['p'];
                 } elseif ( $q['post__in'] ) {
                         $post__in = implode(',', array_map( 'absint', $q['post__in'] ));
-                        $where .= " AND {$wpdb->posts}.ID IN ($post__in)";
+                        $where .= " AND {$this->db->posts}.ID IN ($post__in)";
                 } elseif ( $q['post__not_in'] ) {
                         $post__not_in = implode(',',  array_map( 'absint', $q['post__not_in'] ));
-                        $where .= " AND {$wpdb->posts}.ID NOT IN ($post__not_in)";
+                        $where .= " AND {$this->db->posts}.ID NOT IN ($post__not_in)";
                 }
 
                 if ( is_numeric( $q['post_parent'] ) ) {
-                        $where .= $wpdb->prepare( " AND $wpdb->posts.post_parent = %d ", $q['post_parent'] );
+                        $where .= $this->db->prepare( " AND {$this->db->posts}.post_parent = %d ", $q['post_parent'] );
                 } elseif ( $q['post_parent__in'] ) {
                         $post_parent__in = implode( ',', array_map( 'absint', $q['post_parent__in'] ) );
-                        $where .= " AND {$wpdb->posts}.post_parent IN ($post_parent__in)";
+                        $where .= " AND {$this->db->posts}.post_parent IN ($post_parent__in)";
                 } elseif ( $q['post_parent__not_in'] ) {
                         $post_parent__not_in = implode( ',',  array_map( 'absint', $q['post_parent__not_in'] ) );
-                        $where .= " AND {$wpdb->posts}.post_parent NOT IN ($post_parent__not_in)";
+                        $where .= " AND {$this->db->posts}.post_parent NOT IN ($post_parent__not_in)";
                 }
 
                 if ( $q['page_id'] ) {
                         if  ( ('page' != get_option('show_on_front') ) || ( $q['page_id'] != get_option('page_for_posts') ) ) {
                                 $q['p'] = $q['page_id'];
-                                $where = " AND {$wpdb->posts}.ID = " . $q['page_id'];
+                                $where = " AND {$this->db->posts}.ID = " . $q['page_id'];
                         }
                 }
 
@@ -2816 +2807 @@
                 if ( !$this->is_singular ) {
                         $this->parse_tax_query( $q );
 
-                        $clauses = $this->tax_query->get_sql( $wpdb->posts, 'ID' );
+                        $clauses = $this->tax_query->get_sql( $this->db->posts, 'ID' );
 
                         $join .= $clauses['join'];
                         $where .= $clauses['where'];
@@ -2900 +2891 @@
                 }
 
                 if ( !empty( $this->tax_query->queries ) || !empty( $this->meta_query->queries ) ) {
-                        $groupby = "{$wpdb->posts}.ID";
+                        $groupby = "{$this->db->posts}.ID";
                 }
 
                 // Author/user stuff
@@ -2917 +2908 @@
 
                 if ( ! empty( $q['author__not_in'] ) ) {
                         $author__not_in = implode( ',', array_map( 'absint', array_unique( (array) $q['author__not_in'] ) ) );
-                        $where .= " AND {$wpdb->posts}.post_author NOT IN ($author__not_in) ";
+                        $where .= " AND {$this->db->posts}.post_author NOT IN ($author__not_in) ";
                 } elseif ( ! empty( $q['author__in'] ) ) {
                         $author__in = implode( ',', array_map( 'absint', array_unique( (array) $q['author__in'] ) ) );
-                        $where .= " AND {$wpdb->posts}.post_author IN ($author__in) ";
+                        $where .= " AND {$this->db->posts}.post_author IN ($author__in) ";
                 }
 
                 // Author stuff for nice URLs
@@ -2938 +2929 @@
                         $q['author'] = get_user_by('slug', $q['author_name']);
                         if ( $q['author'] )
                                 $q['author'] = $q['author']->ID;
-                        $whichauthor .= " AND ($wpdb->posts.post_author = " . absint($q['author']) . ')';
+                        $whichauthor .= " AND ({$this->db->posts}.post_author = " . absint($q['author']) . ')';
                 }
 
                 // MIME-Type stuff for attachment browsing
 
                 if ( isset( $q['post_mime_type'] ) && '' != $q['post_mime_type'] )
-                        $whichmimetype = wp_post_mime_type_where( $q['post_mime_type'], $wpdb->posts );
+                        $whichmimetype = wp_post_mime_type_where( $q['post_mime_type'], $this->db->posts );
 
                 $where .= $search . $whichauthor . $whichmimetype;
 
                 if ( ! empty( $this->meta_query->queries ) ) {
-                        $clauses = $this->meta_query->get_sql( 'post', $wpdb->posts, 'ID', $this );
+                        $clauses = $this->meta_query->get_sql( 'post', $this->db->posts, 'ID', $this );
                         $join   .= $clauses['join'];
                         $where  .= $clauses['where'];
                 }
@@ -2970 +2961 @@
                         if ( isset( $q['orderby'] ) && ( is_array( $q['orderby'] ) || false === $q['orderby'] ) ) {
                                 $orderby = '';
                         } else {
-                                $orderby = "$wpdb->posts.post_date " . $q['order'];
+                                $orderby = "{$this->db->posts}.post_date " . $q['order'];
                         }
                 } elseif ( 'none' == $q['orderby'] ) {
                         $orderby = '';
                 } elseif ( $q['orderby'] == 'post__in' && ! empty( $post__in ) ) {
-                        $orderby = "FIELD( {$wpdb->posts}.ID, $post__in )";
+                        $orderby = "FIELD( {$this->db->posts}.ID, $post__in )";
                 } elseif ( $q['orderby'] == 'post_parent__in' && ! empty( $post_parent__in ) ) {
-                        $orderby = "FIELD( {$wpdb->posts}.post_parent, $post_parent__in )";
+                        $orderby = "FIELD( {$this->db->posts}.post_parent, $post_parent__in )";
                 } elseif ( $q['orderby'] == 'post_name__in' && ! empty( $post_name__in ) ) {
-                        $orderby = "FIELD( {$wpdb->posts}.post_name, $post_name__in )";
+                        $orderby = "FIELD( {$this->db->posts}.post_name, $post_name__in )";
                 } else {
                         $orderby_array = array();
                         if ( is_array( $q['orderby'] ) ) {
@@ -3011 +3002 @@
                                 $orderby = implode( ' ' . $q['order'] . ', ', $orderby_array );
 
                                 if ( empty( $orderby ) ) {
-                                        $orderby = "$wpdb->posts.post_date " . $q['order'];
+                                        $orderby = "{$this->db->posts}.post_date " . $q['order'];
                                 } elseif ( ! empty( $q['order'] ) ) {
                                         $orderby .= " {$q['order']}";
                                 }
@@ -3051 +3042 @@
                 }
 
                 if ( isset( $q['post_password'] ) ) {
-                        $where .= $wpdb->prepare( " AND $wpdb->posts.post_password = %s", $q['post_password'] );
+                        $where .= $this->db->prepare( " AND {$this->db->posts}.post_password = %s", $q['post_password'] );
                         if ( empty( $q['perm'] ) ) {
                                 $q['perm'] = 'readable';
                         }
                 } elseif ( isset( $q['has_password'] ) ) {
-                        $where .= sprintf( " AND $wpdb->posts.post_password %s ''", $q['has_password'] ? '!=' : '=' );
+                        $where .= sprintf( " AND {$this->db->posts}.post_password %s ''", $q['has_password'] ? '!=' : '=' );
                 }
 
                 if ( ! empty( $q['comment_status'] ) ) {
-                        $where .= $wpdb->prepare( " AND $wpdb->posts.comment_status = %s ", $q['comment_status'] );
+                        $where .= $this->db->prepare( " AND {$this->db->posts}.comment_status = %s ", $q['comment_status'] );
                 }
 
                 if ( ! empty( $q['ping_status'] ) )  {
-                        $where .= $wpdb->prepare( " AND $wpdb->posts.ping_status = %s ", $q['ping_status'] );
+                        $where .= $this->db->prepare( " AND {$this->db->posts}.ping_status = %s ", $q['ping_status'] );
                 }
 
                 if ( 'any' == $post_type ) {
@@ -3072 +3063 @@
                         if ( empty( $in_search_post_types ) )
                                 $where .= ' AND 1=0 ';
                         else
-                                $where .= " AND $wpdb->posts.post_type IN ('" . join("', '", $in_search_post_types ) . "')";
+                                $where .= " AND {$this->db->posts}.post_type IN ('" . join("', '", $in_search_post_types ) . "')";
                 } elseif ( !empty( $post_type ) && is_array( $post_type ) ) {
-                        $where .= " AND $wpdb->posts.post_type IN ('" . join("', '", $post_type) . "')";
+                        $where .= " AND {$this->db->posts}.post_type IN ('" . join("', '", $post_type) . "')";
                 } elseif ( ! empty( $post_type ) ) {
-                        $where .= " AND $wpdb->posts.post_type = '$post_type'";
+                        $where .= " AND {$this->db->posts}.post_type = '$post_type'";
                         $post_type_object = get_post_type_object ( $post_type );
                 } elseif ( $this->is_attachment ) {
-                        $where .= " AND $wpdb->posts.post_type = 'attachment'";
+                        $where .= " AND {$this->db->posts}.post_type = 'attachment'";
                         $post_type_object = get_post_type_object ( 'attachment' );
                 } elseif ( $this->is_page ) {
-                        $where .= " AND $wpdb->posts.post_type = 'page'";
+                        $where .= " AND {$this->db->posts}.post_type = 'page'";
                         $post_type_object = get_post_type_object ( 'page' );
                 } else {
-                        $where .= " AND $wpdb->posts.post_type = 'post'";
+                        $where .= " AND {$this->db->posts}.post_type = 'post'";
                         $post_type_object = get_post_type_object ( 'post' );
                 }
 
@@ -3114 +3105 @@
                         if ( in_array( 'any', $q_status ) ) {
                                 foreach ( get_post_stati( array( 'exclude_from_search' => true ) ) as $status ) {
                                         if ( ! in_array( $status, $q_status ) ) {
-                                                $e_status[] = "$wpdb->posts.post_status <> '$status'";
+                                                $e_status[] = "{$this->db->posts}.post_status <> '$status'";
                                         }
                                 }
                         } else {
@@ -3121 +3112 @@
                                 foreach ( get_post_stati() as $status ) {
                                         if ( in_array( $status, $q_status ) ) {
                                                 if ( 'private' == $status )
-                                                        $p_status[] = "$wpdb->posts.post_status = '$status'";
+                                                        $p_status[] = "{$this->db->posts}.post_status = '$status'";
                                                 else
-                                                        $r_status[] = "$wpdb->posts.post_status = '$status'";
+                                                        $r_status[] = "{$this->db->posts}.post_status = '$status'";
                                         }
                                 }
                         }
@@ -3138 +3129 @@
                         }
                         if ( !empty($r_status) ) {
                                 if ( !empty($q['perm'] ) && 'editable' == $q['perm'] && !current_user_can($edit_others_cap) )
-                                        $statuswheres[] = "($wpdb->posts.post_author = $user_id " . "AND (" . join( ' OR ', $r_status ) . "))";
+                                        $statuswheres[] = "({$this->db->posts}.post_author = $user_id " . "AND (" . join( ' OR ', $r_status ) . "))";
                                 else
                                         $statuswheres[] = "(" . join( ' OR ', $r_status ) . ")";
                         }
                         if ( !empty($p_status) ) {
                                 if ( !empty($q['perm'] ) && 'readable' == $q['perm'] && !current_user_can($read_private_cap) )
-                                        $statuswheres[] = "($wpdb->posts.post_author = $user_id " . "AND (" . join( ' OR ', $p_status ) . "))";
+                                        $statuswheres[] = "({$this->db->posts}.post_author = $user_id " . "AND (" . join( ' OR ', $p_status ) . "))";
                                 else
                                         $statuswheres[] = "(" . join( ' OR ', $p_status ) . ")";
                         }
                         if ( $post_status_join ) {
-                                $join .= " LEFT JOIN $wpdb->posts AS p2 ON ($wpdb->posts.post_parent = p2.ID) ";
+                                $join .= " LEFT JOIN {$this->db->posts} AS p2 ON ({$this->db->posts}.post_parent = p2.ID) ";
                                 foreach ( $statuswheres as $index => $statuswhere )
-                                        $statuswheres[$index] = "($statuswhere OR ($wpdb->posts.post_status = 'inherit' AND " . str_replace($wpdb->posts, 'p2', $statuswhere) . "))";
+                                        $statuswheres[$index] = "($statuswhere OR ({$this->db->posts}.post_status = 'inherit' AND " . str_replace( $this->db->posts, 'p2', $statuswhere ) . "))";
                         }
                         $where_status = implode( ' OR ', $statuswheres );
                         if ( ! empty( $where_status ) ) {
@@ -3158 +3149 @@
                                 $where .= " AND ($where_status)";
                         }
                 } elseif ( !$this->is_singular ) {
-                        $where .= " AND ($wpdb->posts.post_status = 'publish'";
+                        $where .= " AND ({$this->db->posts}.post_status = 'publish'";
 
                         // Add public states.
                         $public_states = get_post_stati( array('public' => true) );
@@ -3165 +3156 @@
                         foreach ( (array) $public_states as $state ) {
                                 if ( 'publish' == $state ) // Publish is hard-coded above.
                                         continue;
-                                $where .= " OR $wpdb->posts.post_status = '$state'";
+                                $where .= " OR {$this->db->posts}.post_status = '$state'";
                         }
 
                         if ( $this->is_admin ) {
@@ -3172 +3163 @@
                                 // Add protected states that should show in the admin all list.
                                 $admin_all_states = get_post_stati( array('protected' => true, 'show_in_admin_all_list' => true) );
                                 foreach ( (array) $admin_all_states as $state )
-                                        $where .= " OR $wpdb->posts.post_status = '$state'";
+                                        $where .= " OR {$this->db->posts}.post_status = '$state'";
                         }
 
                         if ( is_user_logged_in() ) {
@@ -3179 +3170 @@
                                 // Add private states that are limited to viewing by the author of a post or someone who has caps to read private states.
                                 $private_states = get_post_stati( array('private' => true) );
                                 foreach ( (array) $private_states as $state )
-                                        $where .= current_user_can( $read_private_cap ) ? " OR $wpdb->posts.post_status = '$state'" : " OR $wpdb->posts.post_author = $user_id AND $wpdb->posts.post_status = '$state'";
+                                        $where .= current_user_can( $read_private_cap ) ? " OR {$this->db->posts}.post_status = '$state'" : " OR {$this->db->posts}.post_author = $user_id AND {$this->db->posts}.post_status = '$state'";
                         }
 
                         $where .= ')';
@@ -3230 +3221 @@
                 // Comments feeds
                 if ( $this->is_comment_feed && ! $this->is_singular ) {
                         if ( $this->is_archive || $this->is_search ) {
-                                $cjoin = "JOIN $wpdb->posts ON ($wpdb->comments.comment_post_ID = $wpdb->posts.ID) $join ";
+                                $cjoin = "JOIN {$this->db->posts} ON ({$this->db->comments}.comment_post_ID = {$this->db->posts}.ID) $join ";
                                 $cwhere = "WHERE comment_approved = '1' $where";
-                                $cgroupby = "$wpdb->comments.comment_id";
+                                $cgroupby = "{$this->db->comments}.comment_id";
                         } else { // Other non singular e.g. front
-                                $cjoin = "JOIN $wpdb->posts ON ( $wpdb->comments.comment_post_ID = $wpdb->posts.ID )";
+                                $cjoin = "JOIN {$this->db->posts} ON ( {$this->db->comments}.comment_post_ID = {$this->db->posts}.ID )";
                                 $cwhere = "WHERE ( post_status = 'publish' OR ( post_status = 'inherit' && post_type = 'attachment' ) ) AND comment_approved = '1'";
                                 $cgroupby = '';
                         }
@@ -3293 +3284 @@
                         $cgroupby = ( ! empty( $cgroupby ) ) ? 'GROUP BY ' . $cgroupby : '';
                         $corderby = ( ! empty( $corderby ) ) ? 'ORDER BY ' . $corderby : '';
 
-                        $comments = (array) $wpdb->get_results("SELECT $distinct $wpdb->comments.* FROM $wpdb->comments $cjoin $cwhere $cgroupby $corderby $climits");
+                        $comments = (array) $this->db->get_results("SELECT $distinct {$this->db->comments}.* FROM {$this->db->comments} $cjoin $cwhere $cgroupby $corderby $climits");
                         // Convert to WP_Comment
                         $this->comments = array_map( 'get_comment', $comments );
                         $this->comment_count = count($this->comments);
@@ -3306 +3297 @@
                         $post_ids = join(',', $post_ids);
                         $join = '';
                         if ( $post_ids )
-                                $where = "AND $wpdb->posts.ID IN ($post_ids) ";
+                                $where = "AND {$this->db->posts}.ID IN ($post_ids) ";
                         else
                                 $where = "AND 0";
                 }
@@ -3547 +3538 @@
                 if ( !$q['no_found_rows'] && !empty($limits) )
                         $found_rows = 'SQL_CALC_FOUND_ROWS';
 
-                $this->request = $old_request = "SELECT $found_rows $distinct $fields FROM $wpdb->posts $join WHERE 1=1 $where $groupby $orderby $limits";
+                $this->request = $old_request = "SELECT $found_rows $distinct $fields FROM {$this->db->posts} $join WHERE 1=1 $where $groupby $orderby $limits";
 
                 if ( !$q['suppress_filters'] ) {
                         /**
@@ -3581 +3572 @@
 
                 if ( 'ids' == $q['fields'] ) {
                         if ( null === $this->posts ) {
-                                $this->posts = $wpdb->get_col( $this->request );
+                                $this->posts = $this->db->get_col( $this->request );
                         }
 
                         $this->posts = array_map( 'intval', $this->posts );
@@ -3593 +3584 @@
 
                 if ( 'id=>parent' == $q['fields'] ) {
                         if ( null === $this->posts ) {
-                                $this->posts = $wpdb->get_results( $this->request );
+                                $this->posts = $this->db->get_results( $this->request );
                         }
 
                         $this->post_count = count( $this->posts );
@@ -3611 +3602 @@
                 }
 
                 if ( null === $this->posts ) {
-                        $split_the_query = ( $old_request == $this->request && "$wpdb->posts.*" == $fields && !empty( $limits ) && $q['posts_per_page'] < 500 );
+                        $split_the_query = ( $old_request == $this->request && "{$this->db->posts}.*" == $fields && !empty( $limits ) && $q['posts_per_page'] < 500 );
 
                         /**
                          * Filters whether to split the query.
@@ -3630 +3621 @@
                         if ( $split_the_query ) {
                                 // First get the IDs and then fill in the objects
 
-                                $this->request = "SELECT $found_rows $distinct $wpdb->posts.ID FROM $wpdb->posts $join WHERE 1=1 $where $groupby $orderby $limits";
+                                $this->request = "SELECT $found_rows $distinct {$this->db->posts}.ID FROM {$this->db->posts} $join WHERE 1=1 $where $groupby $orderby $limits";
 
                                 /**
                                  * Filters the Post IDs SQL request before sending.
@@ -3642 +3633 @@
                                  */
                                 $this->request = apply_filters( 'posts_request_ids', $this->request, $this );
 
-                                $ids = $wpdb->get_col( $this->request );
+                                $ids = $this->db->get_col( $this->request );
 
                                 if ( $ids ) {
                                         $this->posts = $ids;
@@ -3652 +3643 @@
                                         $this->posts = array();
                                 }
                         } else {
-                                $this->posts = $wpdb->get_results( $this->request );
+                                $this->posts = $this->db->get_results( $this->request );
                                 $this->set_found_posts( $q, $limits );
                         }
                 }
@@ -3692 +3683 @@
                         /** This filter is documented in wp-includes/query.php */
                         $climits = apply_filters_ref_array( 'comment_feed_limits', array( 'LIMIT ' . get_option('posts_per_rss'), &$this ) );
 
-                        $comments_request = "SELECT $wpdb->comments.* FROM $wpdb->comments $cjoin $cwhere $cgroupby $corderby $climits";
-                        $comments = $wpdb->get_results($comments_request);
+                        $comments_request = "SELECT {$this->db->comments}.* FROM $this->db->comments $cjoin $cwhere $cgroupby $corderby $climits";
+                        $comments = $this->db->get_results($comments_request);
                         // Convert to WP_Comment
                         $this->comments = array_map( 'get_comment', $comments );
                         $this->comment_count = count($this->comments);
@@ -3836 +3827 @@
          * @since 3.5.0
          * @access private
          *
-         * @global wpdb $wpdb WordPress database abstraction object.
-         *
          * @param array  $q      Query variables.
          * @param string $limits LIMIT clauses of the query.
          */
         private function set_found_posts( $q, $limits ) {
-                global $wpdb;
-
                 // Bail if posts is an empty array. Continue if posts is an empty string,
                 // null, or false to accommodate caching plugins that fill posts later.
                 if ( $q['no_found_rows'] || ( is_array( $this->posts ) && ! $this->posts ) )
@@ -3858 +3845 @@
                          * @param string   $found_posts The query to run to find the found posts.
                          * @param WP_Query &$this       The WP_Query instance (passed by reference).
                          */
-                        $this->found_posts = $wpdb->get_var( apply_filters_ref_array( 'found_posts_query', array( 'SELECT FOUND_ROWS()', &$this ) ) );
+                        $this->found_posts = $this->db->get_var( apply_filters_ref_array( 'found_posts_query', array( 'SELECT FOUND_ROWS()', &$this ) ) );
                 } else {
                         $this->found_posts = count( $this->posts );
                 }
@@ -4156 +4143 @@
          *
          * @param string|array $query URL query string or array of vars.
          */
-        public function __construct($query = '') {
-                if ( ! empty($query) ) {
-                        $this->query($query);
+        public function __construct( $query = '' ) {
+                $this->db = $GLOBALS['wpdb'];
+
+                if ( ! empty( $query ) ) {
+                        $this->query( $query );
                 }
         }