Deploy application in windows with driver of postgresql

[Christian Ehrlicher]

Use Dependency Walker or similar to find out what the Qt postgres plugin really needs.

[SGaist]

Hi,

Beside the good advice from @Christian-Ehrlicher, check also the PostgreSQL libraries dependencies.

[MarlonBM]

It is possible that the qpsql library tells me that it depends on a libpq.dll that is not the one inside the application folder?

[SGaist]

Maybe a question of the architecture of the dll you copied.

By the way, unless you added the folder containing the .dll in the search path of Dependency Walker, it will not find it because the plugin is in a different folder.

[MarlonBM]

Before to update this programn, its work Fine with dlls of postgresql for 32 bit. This change could be the problem when i try to compile my programn, but this time with 64 bit?

[jsulm]

@MarlonBM You can't mix 32bit and 64bit in same application.

[MarlonBM]

I get it.
But the version of Qt 5.12.1 comes for 64 bit, and what it has done is compile everything to 64bit, with windeploy it takes all 64 bit dll.
The application works for me, it starts, but the first thing I have is a login form, and when I try to use it, it gives me the driver not loaded error. That is why I think it is the postgres libraries that should be giving me problems.

[jsulm]

@MarlonBM You need 64bit PostgreSQL dll.

[MarlonBM]

on the pc that I have the database,
I have 2 versions of postgres installed, 9.2 of 32 bit, and 11 of 64 bit. I have stopped the postgresql service of the 32-bit one, in case they conflict. I have copied the dll that are in the bin folder of version 11 of 64 bit postgres, for my program folder and it still gives me the same error of
"Driver not load"

[SGaist]

Again: are you sure that the correct dependencies are found ?

[MarlonBM]

Hello,
I have solved with the dependency walker tool,
as advised by @Christian Ehrlicher and @SGaist.
It was not a problem of the postgres dll but it was necessary to install mvcredistx64.