Dear my friends... I am using Qt3.2, Postgres and SuSE 9.1 . I want to use "commit()" and "rollback()" mechanism for my database application. I defined my connection as underbelow: bd = QSqlDatabase::addDatabase("QPSQL7", "OTHER"); bd->setHostName("192.168.23.237"); bd->setDatabaseName("kv"); bd->setUserName("postgres"); bd->setPassword(""); bd->transaction(); if ( ! bd->open() ) { bd->lastError().showMessage(); } But if I execute my application, I find this error message in my linux console: patrixlinux@patrix:~/arsip/proyek/qt/kv/client> QPSQLDriver::beginTransaction: Database not open And I also can do any SQL Query. Where is my fault? Please tell me. Thank you very much in advance. __________________________________ Do you Yahoo!? Yahoo! Mail is new and improved - Check it out! http://promotions.yahoo.com/new_mail