In the sample SQL questions on this site (http://coderunner.org.nz/mod/quiz/view.php?id=194), the following queries both behave as expected on Question 1 (yielding a wrong answer, of course):
select * from customers where city="Paris";
select * from customers where city like "Paris"
Obviously in this question selecting from the non-existent table a gives an error.
What question are you testing with and exactly what error do you get? Please include screen dump(s) showing the question, the answer and the result table, and with the test database file attached. If you have changed the template, we'd need to see that, too.