Changeset 38279

Timestamp:

08/18/2016 07:38:18 PM (8 years ago)

Author:

wonderboymusic

Message:

Query: use composition for $db in WP_Query, removes need to import global $wpdb in multiple methods.

See #37699.

File:

• trunk/src/wp-includes/query.php (modified) (47 diffs)

trunk/src/wp-includes/query.php

@@ -1320 +1320 @@
 
     private $compat_methods = array( 'init_query_flags', 'parse_tax_query' );
+
+    /**
+     * @since 4.7.0
+     * @access protected
+     * @var wpdb
+     */
+    protected $db;
 
     /**
@@ -2115 +2122 @@
      * @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 = '';
 
@@ -2162 +2165 @@
 
             if ( $n && $include ) {
-                $like = '%' . $wpdb->esc_like( $term ) . '%';
-                $q['search_orderby_title'][] = $wpdb->prepare( "$wpdb->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 = '%' . $this->db->esc_like( $term ) . '%';
+                $q['search_orderby_title'][] = $this->db->prepare( "{$this->db->posts}.post_title LIKE %s", $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 = '') ";
+            if ( ! is_user_logged_in() ) {
+                $search .= " AND ({$this->db->posts}.post_password = '') ";
+            }
         }
 
@@ -2257 +2261 @@
      * 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'] );
@@ -2271 +2271 @@
             $like = '';
             if ( ! preg_match( '/(?:\s|^)\-/', $q['s'] ) ) {
-                $like = '%' . $wpdb->esc_like( $q['s'] ) . '%';
+                $like = '%' . $this->db->esc_like( $q['s'] ) . '%';
             }
 
@@ -2278 +2278 @@
             // 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 );
             }
 
@@ -2293 +2293 @@
             // 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 );
             }
 
@@ -2315 +2315 @@
      * @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(
@@ -2369 +2365 @@
             case 'menu_order':
             case 'comment_count':
-                $orderby_clause = "$wpdb->posts.{$orderby}";
+                $orderby_clause = "{$this->db->posts}.{$orderby}";
                 break;
             case 'rand':
@@ -2394 +2390 @@
                 } else {
                     // Default: order by post field.
-                    $orderby_clause = "$wpdb->posts.post_" . sanitize_key( $orderby );
+                    $orderby_clause = "{$this->db->posts}.post_" . sanitize_key( $orderby );
                 }
 
@@ -2481 +2477 @@
      * @access public
      *
-     * @global wpdb $wpdb WordPress database abstraction object.
-     *
      * @return array List of posts.
      */
     public function get_posts() {
-        global $wpdb;
-
         $this->parse_query();
 
@@ -2623 +2615 @@
         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.*";
-        }
-
-        if ( '' !== $q['menu_order'] )
-            $where .= " AND $wpdb->posts.menu_order = " . $q['menu_order'];
-
+                $fields = "{$this->db->posts}.*";
+        }
+
+        if ( '' !== $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($q['m'], 0, 4);
-            if ( strlen($q['m']) > 5 )
-                $where .= " AND MONTH($wpdb->posts.post_date)=" . substr($q['m'], 4, 2);
-            if ( strlen($q['m']) > 7 )
-                $where .= " AND DAYOFMONTH($wpdb->posts.post_date)=" . substr($q['m'], 6, 2);
-            if ( strlen($q['m']) > 9 )
-                $where .= " AND HOUR($wpdb->posts.post_date)=" . substr($q['m'], 8, 2);
-            if ( strlen($q['m']) > 11 )
-                $where .= " AND MINUTE($wpdb->posts.post_date)=" . substr($q['m'], 10, 2);
-            if ( strlen($q['m']) > 13 )
-                $where .= " AND SECOND($wpdb->posts.post_date)=" . substr($q['m'], 12, 2);
+            $where .= " AND YEAR({$this->db->posts}.post_date)=" . substr($q['m'], 0, 4);
+            if ( strlen($q['m']) > 5 ) {
+                $where .= " AND MONTH({$this->db->posts}.post_date)=" . substr($q['m'], 4, 2);
+            }
+            if ( strlen($q['m']) > 7 ) {
+                $where .= " AND DAYOFMONTH({$this->db->posts}.post_date)=" . substr($q['m'], 6, 2);
+            }
+            if ( strlen($q['m']) > 9 ) {
+                $where .= " AND HOUR({$this->db->posts}.post_date)=" . substr($q['m'], 8, 2);
+            }
+            if ( strlen($q['m']) > 11 ) {
+                $where .= " AND MINUTE({$this->db->posts}.post_date)=" . substr($q['m'], 10, 2);
+            }
+            if ( strlen($q['m']) > 13 ) {
+                $where .= " AND SECOND({$this->db->posts}.post_date)=" . substr($q['m'], 12, 2);
+            }
         }
 
@@ -2710 +2707 @@
 
         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'] ) );
         }
 
@@ -2716 +2713 @@
         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) ) {
@@ -2745 +2742 @@
                 $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 ) {
@@ -2757 +2754 @@
             $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)";
         }
 
@@ -2770 +2767 @@
         // 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)";
         }
 
@@ -2792 +2789 @@
             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'];
             }
         }
@@ -2817 +2814 @@
             $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'];
@@ -2901 +2898 @@
 
         if ( !empty( $this->tax_query->queries ) || !empty( $this->meta_query->queries ) ) {
-            $groupby = "{$wpdb->posts}.ID";
+            $groupby = "{$this->db->posts}.ID";
         }
 
@@ -2918 +2915 @@
         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) ";
         }
 
@@ -2939 +2936 @@
             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 );
-
+        if ( isset( $q['post_mime_type'] ) && '' != $q['post_mime_type'] ) {
+            $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'];
@@ -2971 +2968 @@
                 $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();
@@ -3012 +3009 @@
 
                 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']}";
@@ -3052 +3049 @@
 
         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 ) {
             $in_search_post_types = get_post_types( array('exclude_from_search' => false) );
-            if ( empty( $in_search_post_types ) )
+            if ( empty( $in_search_post_types ) ) {
                 $where .= ' AND 1=0 ';
-            else
-                $where .= " AND $wpdb->posts.post_type IN ('" . join("', '", $in_search_post_types ) . "')";
+            } else {
+                $where .= " AND {$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' );
         }
@@ -3115 +3113 @@
                 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'";
                     }
                 }
@@ -3121 +3119 @@
                 foreach ( get_post_stati() as $status ) {
                     if ( in_array( $status, $q_status ) ) {
-                        if ( 'private' == $status )
-                            $p_status[] = "$wpdb->posts.post_status = '$status'";
-                        else
-                            $r_status[] = "$wpdb->posts.post_status = '$status'";
+                        if ( 'private' == $status ) {
+                            $p_status[] = "{$this->db->posts}.post_status = '$status'";
+                        } else {
+                            $r_status[] = "{$this->db->posts}.post_status = '$status'";
+                        }
                     }
                 }
@@ -3138 +3137 @@
             }
             if ( !empty($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 ', $r_status ) . "))";
-                else
+                if ( !empty($q['perm'] ) && 'editable' == $q['perm'] && !current_user_can($edit_others_cap) ) {
+                    $statuswheres[] = "({$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 ', $p_status ) . "))";
-                else
+                if ( !empty($q['perm'] ) && 'readable' == $q['perm'] && !current_user_can($read_private_cap) ) {
+                    $statuswheres[] = "({$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) ";
-                foreach ( $statuswheres as $index => $statuswhere )
-                    $statuswheres[$index] = "($statuswhere OR ($wpdb->posts.post_status = 'inherit' AND " . str_replace($wpdb->posts, 'p2', $statuswhere) . "))";
+                $join .= " LEFT JOIN {$this->db->posts} AS p2 ON ({$this->db->posts}.post_parent = p2.ID) ";
+                foreach ( $statuswheres as $index => $statuswhere ) {
+                    $statuswheres[$index] = "($statuswhere OR ({$this->db->posts}.post_status = 'inherit' AND " . str_replace( $this->db->posts, 'p2', $statuswhere ) . "))";
+                }
             }
             $where_status = implode( ' OR ', $statuswheres );
@@ -3159 +3161 @@
             }
         } elseif ( !$this->is_singular ) {
-            $where .= " AND ($wpdb->posts.post_status = 'publish'";
+            $where .= " AND ({$this->db->posts}.post_status = 'publish'";
 
             // Add public states.
@@ -3166 +3168 @@
                 if ( 'publish' == $state ) // Publish is hard-coded above.
                     continue;
-                $where .= " OR $wpdb->posts.post_status = '$state'";
+                $where .= " OR {$this->db->posts}.post_status = '$state'";
             }
 
@@ -3172 +3174 @@
                 // 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'";
+                foreach ( (array) $admin_all_states as $state ) {
+                    $where .= " OR {$this->db->posts}.post_status = '$state'";
+                }
             }
 
@@ -3179 +3182 @@
                 // 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'";
+                foreach ( (array) $private_states as $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'";
+                }
             }
 
@@ -3231 +3235 @@
         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 = '';
@@ -3294 +3298 @@
             $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 );
@@ -3306 +3310 @@
             $post_ids = join(',', $post_ids);
             $join = '';
-            if ( $post_ids )
-                $where = "AND $wpdb->posts.ID IN ($post_ids) ";
-            else
+            if ( $post_ids ) {
+                $where = "AND {$this->db->posts}.ID IN ($post_ids) ";
+            } else {
                 $where = "AND 0";
+            }
         }
 
@@ -3548 +3553 @@
             $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'] ) {
@@ -3582 +3587 @@
         if ( 'ids' == $q['fields'] ) {
             if ( null === $this->posts ) {
-                $this->posts = $wpdb->get_col( $this->request );
+                $this->posts = $this->db->get_col( $this->request );
             }
 
@@ -3594 +3599 @@
         if ( 'id=>parent' == $q['fields'] ) {
             if ( null === $this->posts ) {
-                $this->posts = $wpdb->get_results( $this->request );
+                $this->posts = $this->db->get_results( $this->request );
             }
 
@@ -3612 +3617 @@
 
         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 );
 
             /**
@@ -3631 +3636 @@
                 // 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";
 
                 /**
@@ -3643 +3648 @@
                 $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 ) {
@@ -3653 +3658 @@
                 }
             } else {
-                $this->posts = $wpdb->get_results( $this->request );
+                $this->posts = $this->db->get_results( $this->request );
                 $this->set_found_posts( $q, $limits );
             }
@@ -3693 +3698 @@
             $climits = apply_filters_ref_array( 'comment_feed_limits', array( 'LIMIT ' . get_option('posts_per_rss'), &$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 );
@@ -3837 +3842 @@
      * @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 $wpdb;
-
         // Bail if posts is an empty array. Continue if posts is an empty string,
         // null, or false to accommodate caching plugins that fill posts later.
@@ -3859 +3860 @@
              * @param WP_Query &$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 );
@@ -4157 +4158 @@
      * @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 );
         }
     }