"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 Command.