I have add C:\mysql\mysql-5.7.21-winx64\lib into path variable. but don't work!

@mrjj Many thanks mrjj for your answer. I'll make more researches about SQLite and Taglib.

@tskardal said in How do you persist and update your models?: I'm thinking that the goal is having "plain" models that are not QObjects. That's a quite normal thing to do. Let the Qt model be just an intermediary between actual data model/tree and the GUI. If your implementation works, then it's OK I guess. I'm not sure if there any actual question to answer here :-)

@aha_1980 Unfortunately the link http://www.qtrpt.tk is no more working. To get official source of the project please use https://sourceforge.net/p/qtrpt/discussion/general/

Hi, Are you aware of the implications of moving from MySQL to SQLite ? One of which is: you are using a relative path for your SQLite database which won't work if your users install your application in e.g. Program Files as it's a read-only location.

Hi, To add to @dream_captain, in case of an error, at least print the error string from the query so you know what went wrong.

The most compatible with qt is GE Predix (https://www.predix.io/) - https://github.com/IndeemaSoftware/QPredix

@Kushan Or you can use resizeColumnsToContents() method for the same.

@abforce said in Looking for the best multithreading patterns for database access: For this purpose can I employ a callback pattern? You can simply use signals/slots across threads

@SGaist Thank you for your answer!

@Lasith You should open the database only once. Currently you do it each time button is pressed.

Hi, There's no need for any global objects all the more if you only have one active connection for your application but it's also valid if you are managing multiple connections. The QSqlDatabase class already provides everything you need. Like written in the documentation, if you are only using one connection, don't give it a name, it will become the default connection and all the SQL related classes will use it by default. If you have several connections, it's easy to retrieve the one you are interested in by using QSqlDatabase::database. On a side note, you should properly test the outcome of your open call. Right now it could be failing and you don't care about that possibility.

@mostefa said in connecting to database when a form loads using signals and slots: I think that this post is duplicate Strictly speaking it isn't, although it's quite similar.

@mostefa Thanx mate

@spektro37 Well its used with all QWidgets so would make sense. Its something to be aware of when creating GUI and also the little note that any QWidget that are not given a owner/parent, will become a window. That can be surprised when coming from other frameworks. Say you make a new label QLabel *lab= new QLabel(); Since its given no parent, it will become a window. That was pretty surprising to me first time as i wanted to insert it into the main window. So its good to know about.