58: error: QSqlRelationalDelegate: No such file or directory

[Gianfranco Facchini]

Hello, I'm a new aspiring programmer in QT. I'm following the example books.
When I try build project I have this error:
.. \books\bookdelegate.h:58: error: QSqlRelationalDelegate: No such file or directory

In file i have declare :
#include <QSqlRelationalDelegate>

when i build i use C:\Qt\Tools\mingw530_32\bin\mingw32-make.exe
what is the problem?

be patient, I'm a programmer but now I'm starting to study C ++ and QT.

Thanks

[mchinand]

Do you have QT += sql in your project file (.pro)?

[SGaist]

Hi and welcome to devnet,

To add to @mchinand, don't forget to re-run qmake before building after adding QT += sql to your .pro file.

[mrjj]

Hi
A slightly longer story
When the Qt feature lives in a module
http://doc.qt.io/qt-5/qtmodules.html
Like SQL does.
The docs tells what to add to the project file. ( the . pro file )
for that class.
it looks like
qmake: QT += name

often in big box.

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