"field | variable" is not unique and must be qualified (Error 1832)

You have referenced a field that exists in more than one table.

For example, if you use the TESTDATA database and issue the following command, the same error occurs because the cust_id field exists in both the customer and orders tables:

SELECT cust_id FROM customer,orders

• To work around the non-uniqueness of field names, issue the following command:

  SELECT customer.cust_id FROM customer,orders
  

  For more information, see SELECT - SQL.