MDL-29198 DB - make delete_records transactional safe when needed

moodle · Sep 1, 2011 · 687e61c · 687e61c
1 parent 15141ad
commit 687e61c
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Showing 2 changed files with 22 additions and 1 deletion.
diff --git a/lib/dml/moodle_database.php b/lib/dml/moodle_database.php
@@ -1575,7 +1575,9 @@ public function record_exists_sql($sql, array $params=null) {
      * @throws dml_exception if error
      */
     public function delete_records($table, array $conditions=null) {
-        if (is_null($conditions)) {
+        // truncate is drop/create (DDL), not transactional safe,
+        // so we don't use the shortcut within them. MDL-29198
+        if (is_null($conditions) && empty($this->transactions)) {
             return $this->execute("TRUNCATE TABLE {".$table."}");
         }
         list($select, $params) = $this->where_clause($table, $conditions);

diff --git a/lib/dml/simpletest/testdml.php b/lib/dml/simpletest/testdml.php
@@ -3771,6 +3771,25 @@ function test_concurent_transactions() {
         $transaction->allow_commit();
         $this->assertEqual(2, $DB2->count_records($tablename));
 
+        // let's try delete all is also working on (this checks MDL-29198)
+        // initially both connections see all the records in the table (2)
+        $this->assertEqual(2, $DB->count_records($tablename));
+        $this->assertEqual(2, $DB2->count_records($tablename));
+        $transaction = $DB->start_delegated_transaction();
+
+        // delete all from within transaction
+        $DB->delete_records($tablename);
+
+        // transactional $DB, sees 0 records now
+        $this->assertEqual(0, $DB->count_records($tablename));
+
+        // others ($DB2) get no changes yet
+        $this->assertEqual(2, $DB2->count_records($tablename));
+
+        // now commit and we should see changes
+        $transaction->allow_commit();
+        $this->assertEqual(0, $DB2->count_records($tablename));
+
         $DB2->dispose();
     }