[SOLVED] <QSqlQuery> vs <QtSql/QSqlQuery>

[Resurrection]

Solved: The qmake module include must be present in all projects using it even indirectly.

I was used to add modules to qmake:

@
QT += sql
@

and then including the classes as:

@
#include <QSqlQuery>
@

however recently in my plugins/libraries based project I can compile the plugin just fine with the above but when compiling the whole project I get this error:

@
QSqlQuery: No such file or directory
@

Oddly simply replacing the include with:

@
#include <QtSql/QSqlQuery>
@

works fine. Why is that? Thx.

Note: I am using Qt 5.3 and the class header that uses this include is located in a shared library so the class is being exported with Q_DECL_EXPORT if that is of any significance.

[mbnoimi]

AFAIK there is no difference but try to use the following instead:
[code]#include <QtSql>[/code]

I usually use it for accessing all SQL classes

[SGaist]

Hi,

What do you mean by all project vs plugin ?

On a side note, using module include is a bad habit, while it's ok for rapid prototyping, it should be avoided as it pulls in everything from the module and thus slows down the whole compilation process.

[Resurrection]

2mbnoimi: All sql family includes do not work when used plainly without the qtsql/ (nor does whole module) directory specified with the same error as in OP.

2SGaist: I have a subdirs project with 2 apps, 3 shared libraries and several dynamic plugins. The problem occurs with one of the libraries. When I compile it on its own (right-click in Creator -> Build/Rebuild) it compiles fine. But when I build one of the apps using it (which also builds the linked libraries) it gives me the error above.

[vezprog]

Does each of the sub projects that use the SQL plugin have QT += sql in their .pro files?

When you have a sub project that is a shared library, the shared library requires the Qt module in the .pro as well as the project including files located in the shared library.

I have had to do this before, try adding QT += sql in the .pro file of the app including files from the shared library.

[Resurrection]

2devz43: Thanks, this solved the problem!