Problem: "QSqlDatabase: QPSQL driver not loaded" (Windows OS)

[faldzip]

In general it means that you don't have QPSQL driver which is needed for connecting to PostgreSQL. For more information look here: http://doc.trolltech.com/4.5/sql-dri...-7-3-and-above. There is also link at the end of that part: Compiling PostgreSQL On Native Win32 FAQ.

[spirit]

try to search by forum, this question was discussed many times.

[Alberto++]

Oks, thanks, I'll try those webs, faldżip. If I get blocked I'll continue searching in the forum. And if I don't solve the problem I'll ask again =).

[feraudyh]

Hi, I landed on this problem myself. I'm on windows and there is a special warning I would like to share with newbies like me:
if you want to compile the Postgresdriver for windows and you have installed Postgres on
c:\program files\Postgres\8.4
then the space in the path means you cant just modify the example suggested in the Qt documentation by simple substitution.
In other words the following call to qmake will not work
qmake "INCLUDEPATH+=C:\Program Files\PostgreSQL\8.4\include" "LIBS+=C:\Program Files\PostgreSQL\8.4\lib\libpq.lib" psql.pro
One way of getting around the problem is to
fix the makefile which contains the following incorrect assignments inside the definition of
INCPATH
-I"c:\Program" -I"Files\PostgreSQL\8.4\include"
replace these by
-I"c:\Program Files\PostgreSQL\8.4\include"

I dont know about doubling up the double quotes inside the strings ,maybe that's a better solution! In any case the user should be warned.