Различия

Здесь показаны различия между двумя версиями данной страницы.

--- dev:qt:qt_ibase_fix_commit [2015/05/20 13:52]
denis создано
+++ dev:qt:qt_ibase_fix_commit [2015/05/20 14:41] (текущий)
denis [the solution]
@@ Строка 16: / Строка 16: @@
 end
 </code>
+  - qt code:<code cpp>
+  QSqlDatabase db = ...
+  QString sql = "drop sequence myseq";
+  db.transaction();
+  QSqlQuery q(sql, db);
+  qDebug() << q.lastError().text(); // no error!
+  q.close();
+  db.commit();
+  qDebug() << q.lastError().text(); // error: unsuccessful metadata update...
+  // trying to drop once more time
+  db.transaction();
+  QSqlQuery q(sql, db); // blocked forever...
+</code>
+==== the solution ====
+Edit file ''.../qtbase/src/sql/drivers/ibase/qsql_ibase.cpp'':
+<code cpp>
+bool QIBaseDriver::commitTransaction()
+{
+    Q_D(QIBaseDriver);
+    if (!isOpen() || isOpenError())
+        return false;
+    if (!d->trans)
+        return false;
+    isc_commit_transaction(d->status, &d->trans);
+//    d->trans = 0;
+//    return !d->isError(QT_TRANSLATE_NOOP("QIBaseDriver", "Unable to commit transaction"),
+//                       QSqlError::TransactionError);
+    bool res = !d->isError(QT_TRANSLATE_NOOP("QIBaseDriver", "Unable to commit transaction"),
+                       QSqlError::TransactionError);
+    if( !res )
+        isc_rollback_transaction(d->status, &d->trans);
+    d->trans = 0;
+    return res;
+}
+</code>
+==== ps ====
+Prefer explicit transation **start** and **commit** as shown above because it is not possible to avoid this problem executing queries with implicit transaction control.