Hello Mark, Am Freitag, 4. Januar 2013, 12:03:22 schrieb Mark Brand: > > i ran into an issue using transactions together with QSqlTableModel. > > > > Whenever i do a "QSqlDatabase::rollback ()" the QSqlTableModel internal > > buffer is not updated to reflect this. So it still shows the data before > > the rollback. > > I'm not sure whether your "internal buffer" refers to caching of query > results or edited rows.
The latter one. Submit policy actually is kept default which is, if i remember correctly, going after rows. > QSqlTableModel doesn't cache the query results. > It's base class QSqlQueryModel just provides a model interface to > QSqlQuery which wraps QSqlResult. QSqlResult has a driver-specific > implementation that may or may not cache locally. QSqlTableModel does > cache edited rows however. This is the culprit. I have several views on it. If i start a transaction, do an edit (without submit) and a rollback the other views still show the edited value before rollback. Calling revert(All) exits the program an "vector indes out of range". A call to select exhibits the same behavior (as it does - as far as know - also call revert(All) internally). > > Is there a signal or other method to detect a rollback ? > > This allows me to re-load the tables and views. > > There is no general automatic mechanism to refresh queries when the > database changes. Your application will have to do this. Probably you > will want to call QSqlTableModel::select() to refresh when necessary. > This resets the model and view and reverts all unsubmitted edits. You > might be able to use QSqlDriver notifications to detect database changes > if the driver you are using supports them. The last knowledge i have (from Qt 4.4 era) is that the mysql driver does not support it. > > NB.: If i do a revert or select call on QSqlDatabase having un-submitted > > data after the rollback i get a 'Vector index out of range' trap from > > inside the qt-lib. This might be a coding error of me. But if anyone has > > a similar experience and could give me a helping hand ... > > I am actually on the way of tracking down this issue. > > > > I currently use Qt 4.8.4 and gcc 4.5.4 on Linux (x86_64). > > The database server is MariaDB 5.5.23 > > The scenario you describe is not completely clear to me. If you can > reproduce and isolate the problem, it would probably be best to file a > bug report, preferably with a simple demo. Will do. Somewhere inside the QSortFilterProxyModel/dataChanged it accesses a column too far (table has 15 columns, the vector index used is 15 - one too much). At the moment i have a workaround. Calling submit(All) before rollback allows me to do a select call after the rollback without aborting the program. > > Are there any hints ? > > I recommend using Qt 5 if possible. There are significant behavior > changes in QSqlTableModel that might be of benefit, and you can avoid > the extra work of porting your application to Qt 5 later. Its on my task list. Due the program should also run on windows platforms i need to have one ready. At the moment i have problems establishing an installation on Windows (32/64 Bit) using the MinGW compiler. Currently there is no downloadable Qt5 installation pack at digia for MinGW - only one for the VS compiler. <dream on>If it comes bundled with the Mysql/MariaDB client lib released by MariaDB under LGPL i woud be happy. No more need to install the source on windows only to compile the plugin</dream off> regards Petric _______________________________________________ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
