PyQt exclusive OR in sql query - sql

Question

How can I make that if my first search shows results it doesn't do the second part of the query, but stops and displays results? I tried something like this, but it just gives me blank window and it's pretty chaotic:
def test_update(self):
projectModel = QSqlQueryModel()
projectModel.setQuery("""SELECT * FROM pacijent WHERE prezime = '%s' OR (prezime, 3) = metaphone('%s', 3) OR LEVENSHTEIN(LOWER(prezime), '%s') < 3 AND NOT (prezime = '%s' AND (prezime, 3) = metaphone('%s', 3) AND LEVENSHTEIN(LOWER(prezime), '%s') < 3)""" % (str(self.lineEdit.text()), str(self.lineEdit.text()), str(self.lineEdit.text()), str(self.lineEdit.text()), str(self.lineEdit.text()), str(self.lineEdit.text())))
global projectView
projectView = QtGui.QTableView()
projectView.setModel(projectModel)
projectView.show()
So, if it finds the exact value of attribute "prezime" it should display it, but if it doesn't it should call for more advance saerch tactics, such as metaphone and levenshtein.
EDIT:
I got it working like this:
ef search_data(self):
myQSqlQueryModel = QSqlQueryModel()
query = QSqlQueryModel()
global myQTableView
myQTableView = QtGui.QTableView()
querySuccess = False
for queryCommand in [""" SELECT * FROM "%s" WHERE "%s" = '%s' """ % (str(self.search_from_table_lineEdit.text()), str(self.search_where_lineEdit.text()), str(self.search_has_value_lineEdit.text()))]:
myQSqlQueryModel.setQuery(queryCommand)
if myQSqlQueryModel.rowCount() > 0:
myQTableView.setModel(myQSqlQueryModel)
myQTableView.show()
querySuccess = True
break
if not querySuccess:
query.setQuery(""" SELECT * FROM "%s" WHERE METAPHONE("%s", 3) = METAPHONE('%s', 3) OR LEVENSHTEIN("%s", '%s') < 4 """ % (str(self.search_from_table_lineEdit.text()), str(self.search_where_lineEdit.text()), str(self.search_has_value_lineEdit.text()), str(self.search_where_lineEdit.text()), str(self.search_has_value_lineEdit.text())))
global var
var = QtGui.QTableView()
var.setModel(query)
var.show()

Answer 1

After your query success, your can check your data in model if have any row count in this method. And your for loop to get many query;
def testUpdate (self):
myQSqlQueryModel = QtSql.QSqlQueryModel()
myQTableView = QtGui.QTableView()
querySuccess = False
for queryCommand in ["YOUR QUERY 1", "YOUR QUERY 2"]:
myQSqlQueryModel.setQuery(queryCommand)
if myQSqlQueryModel.rowCount() > 0:
myQTableView.setModel(myQSqlQueryModel)
myQTableView.show()
querySuccess = True
break
if not querySuccess:
QtGui.QMessageBox.critical(self, 'Query error', 'Not found')