Issue #2042239 by lucaslg, tbradbury, snehi, pkiraly, pjonckiere, ori…

…ol_e9g, ivanchaer, jhodgdon, chx, cilefen, David_Rothstein: Fix DeleteQuery::execute() return value documentation and DeleteQuery_sqlite documentation

includes/database/query.inc

@@ -845,8 +845,8 @@ class DeleteQuery extends Query implements QueryConditionInterface {
   /**
    * Executes the DELETE query.
    *
-   * @return
-   *   The return value is dependent on the database connection.
+   * @return int
+   *   The number of rows affected by the delete query.
    */
   public function execute() {
     $values = array();

includes/database/sqlite/query.inc

@@ -99,16 +99,15 @@ class UpdateQuery_sqlite extends UpdateQuery {
 
 /**
  * SQLite specific implementation of DeleteQuery.
- *
- * When the WHERE is omitted from a DELETE statement and the table being deleted
- * has no triggers, SQLite uses an optimization to erase the entire table content
- * without having to visit each row of the table individually.
- *
- * Prior to SQLite 3.6.5, SQLite does not return the actual number of rows deleted
- * by that optimized "truncate" optimization.
  */
 class DeleteQuery_sqlite extends DeleteQuery {
   public function execute() {
+    // When the WHERE is omitted from a DELETE statement and the table being
+    // deleted has no triggers, SQLite uses an optimization to erase the entire
+    // table content without having to visit each row of the table individually.
+    // Prior to SQLite 3.6.5, SQLite does not return the actual number of rows
+    // deleted by that optimized "truncate" optimization. But we want to return
+    // the number of rows affected, so we calculate it directly.
     if (!count($this->condition)) {
       $total_rows = $this->connection->query('SELECT COUNT(*) FROM {' . $this->connection->escapeTable($this->table) . '}')->fetchField();
       parent::execute();