I have some questions for you:

I created a python-plugin in QGIS,

then I created a Qt gui fom my plugin

and at last I created a Postgres DB

now I need to make a connection between Qt-gui and Postgres-DB

I wrote this

 from PyQt4.QtSql import *
 db = QSqlDatabase.addDatabase("QPSQL");
 bool ok = db.open();

but it doesn't works, I can't understand what I do wrong...

I wish someone could help me...

thank you for all! lisa

  • 3
    check what the db.lastError() method returns – Nathan W Jul 17 '12 at 14:23
  • 1
    port=5432 is required even on localhost – Mapperz Jul 17 '12 at 14:34

Here is a good tutorial that helped me a lot:


update The above link has expired... :(

Here is my code that I use in my QGIS plugin:

from PyQt4.QtSql import *
db = QSqlDatabase('QPSQL')
if db.isValid():
    # string
    # string
    # string
    # string
    # integer e.g. 5432
    if db.open():
        # assume you have a table called 'users'
        query = db.exec_("""select * from users""")
        # iterate over the rows
        while query.next(): 
            record = query.record()
            # print the value of the first column
            print record.value(0) 

Hope that helps.

  • Can you elaborate on your answer just a little? Perhaps you could include a short summary of the main points as they relate to the question? Thanks. – WhiteboxDev Oct 1 '14 at 14:24
  • updated and added code snippet. – fegyi001 Oct 7 '14 at 11:56

I had also problems with QSqlDatabase, so I used the psycopg2 library instead:


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