Inner Joining the same table multiple times

Question

So I have received this error: #1066 - Not unique table/alias: \'Purchase\'

I am trying to do the following:

    SELECT Blank.BlankTypeCode
              


        

Answer 1

You need a different alias for the table each time you use it.

SELECT B.BlankTypeCode, B.BlankCode, A1.Amount, A1.Type, P1.PurchaseDate, P1.DatePaid
  FROM Blank AS B
  JOIN Ticket    AS T  ON B.BlankCode = T.Blank_BlankCode
  JOIN MCO_Blank AS M  ON B.BlankCode = M.Blank_BlankCode
  JOIN Purchase  AS P1 ON T.PurchaseID = P1.PurchaseID
  JOIN Purchase  AS P2 ON M.PurchaseID = P2.PurchaseID
  JOIN Payment   AS A1 ON T.PurchaseID = A1.PurchaseID
  JOIN Payment   AS A2 ON M.PurchaseID = A2.PurchaseID
 WHERE A1.Status = "Paid"
   AND A2.Status = "Paid"

You'll need to sort out which versions of the Purchase and Payment tables the selected columns come from, and also what should be in the WHERE clause really.