Error 1052 Field is Ambiguous using Inner Join Function Error '1052' Field is ambiguous. I understand the error that is happening, and I've looked at several places for the fix and then applied the inner join function in attempt to fix it. It's still not working, and it gives me the same error.

EventNo is a primary key in the eventrequest table and a foreign key in the Eventplan table. I'm trying to list the event number, event date, and count of the event plans while only including event requests in the result if the event request has more than one related event plan with a work date in December 2013. This is my code.

SELECT EventNo, DateAuth, COUNT(PlanNo)
FROM eventplan INNER JOIN eventrequest ON eventplan.eventNo = Eventrequest.EventNo
WHERE COUNT(PlanNo) &gt; 1 BETWEEN '2013-12-01' AND '2013-12-31';
Qualify each column in the SELECT/WHERE and join clauses.

So, for example I've qualified the EventNo column so that it's read from the eventplan table in the SELECT clause - it's ambiguous because it is in both the eventplan and eventrequest tables.

SELECT eventplan.EventNo, DateAuth, COUNT(PlanNo)
FROM eventplan INNER JOIN eventrequest ON eventplan.eventNo = Eventrequest.EventNo
WHERE COUNT(PlanNo) &gt; 1 BETWEEN '2013-12-01' AND '2013-12-31';


You may nave to do the same for DateAuth and PlanNo if they exist in both tables (in this specific query).

It's good practice to always fully qualify column names - can make the query easier to read. You can always use a table alias too to cut down on typing.