Hello, Be careful of mixing thread and mysql :
https://bugreports.qt-project.org/browse/QTBUG-31468 You should protect the calls to addDatabase with a mutex. Le 30/05/2013 18:31, Karl Ruetz a écrit :
Both the documentation and my own experience say what you are after is not possible:http://qt-project.org/doc/qt-4.8/threads-modules.html#threads-and-the-sql-moduleI do a similar thing only with MySQL. I am forced to create a QSqlDatabase object with each thread. If I do not, I get dead locked situations once in awhile. With Sqlite, I would think there would be some I/O conflicts since the database is actually a file.A connection per thread seems the only safe way to approach it. Karl On 2013-05-30 10:03, Witold E Wolski wrote:I am using threading to speed up compuation. Each thread produces some results which I would like to store in a sqlite file.My idea is to have something like an monitor object which has an QSqlDatabase memberand a insert method which is synchronized using a mutex.The problem I am actually running into is that the QSqlDatabase member gets ??? once the pointer to the Monitor object is passed into to the threads.when asked in the thread it claims to be isOpen and to be isValid but all the inserts on it fail withinsert Feature: Parameter count mismatchOn the other hand if I construct the same object within the thread than everything works fine.So the instert statements are definitely correct. Any ideas ? by the way I am using the tbb for threading. Witold _______________________________________________ Interest mailing list Interest@qt-project.org <mailto:Interest@qt-project.org> http://lists.qt-project.org/mailman/listinfo/interest_______________________________________________ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
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