Crashing on db.exec_ when the file is run for the second time

knee_boarder

I have two issues - first off (and more importantly) the second time the code is run from the QGIS Python console it fails with "The thread tried to read from or write to a virtual address for which it does not have the appropriate access". It's crashing on db.exec_

The db is SQL Server 2008 r2 and we're running the 32bit version of QGIS.

The second issue is that if I close and remove the database the table displayed using projectView.show() is empty yet if I comment those lines out, the data displays correctly.

@from PyQt4.QtSql import *
from PyQt4.QtGui import *
from qgis.gui import *

db = QSqlDatabase.addDatabase('QODBC')
if db.isValid():
db.setDatabaseName('DRIVER={SQL Server};SERVER=%s;DATABASE=%s;UID=%s;PWD=%s;'
% ('ServerName',
'Database',
'username',
'password'))

#print "db.isValid"

if db.open():
    #print "success"
    query = db.exec_("""SELECT TOP 100 postal_address as address, EASTING as x, NORTHING as y FROM dbo.POSTAL_ADDRESS WHERE postal_address LIKE('%EX3 %')""")

    projectModel = QSqlQueryModel()
    projectModel.setQuery(query)
    projectView = QTableView()
    projectView.setModel(projectModel)

    projectView.show()    

    QMessageBox.warning(None, "Info", "hello")

    query = db.exec_("""SELECT TOP 100 postal_address as address, EASTING as x, NORTHING as y FROM dbo.POSTAL_ADDRESS WHERE postal_address LIKE('%EX2 %')""")

    projectModel = QSqlQueryModel()
    projectModel.setQuery(query)
    projectView = QTableView()
    projectView.setModel(projectModel)

    projectView.show()    

    #db.close()
    #db.removeDatabase('QODBC')       

else:
    QMessageBox.warning(None, "Info", "Error")

else:
QMessageBox.warning(None, "Info", "Error")@

The error is

Dump Summary ------------
Dump File: qgis-20141218-083144-1364-7108-exported.dmp : C:\Users\usr\AppData\Local\Temp\qgis-20141218-083144-1364-7108-exported.dmp
Last Write Time: 18/12/2014 08:31:44
Process Name: qgis-bin.exe : C:\Program Files\QGIS Brighton\bin\qgis-bin.exe
Process Architecture: x64
Exception Code: 0xC0000005
Exception Information: The thread tried to read from or write to a virtual address for which it does not have the appropriate access.
Heap Information: Not Present –

When the file is run in the QGIS python console the first time, both db.exec_ calls work correctly. When the file is run for the second time, that's when the crash occurs. Could it be an x32 / x64 error? The code I was trying to change originally postgissearch worked fine when connecting to a postgis database but now I'm trying to connect to a sql server db I get the error the second time it runs and the table doesn't display data if I close and remove the database.