Bob,
If u insert the following data
INSERT INTO A
SELECT 4,1,'TABLE_2','COLUMN_1',678
INSERT INTO A
SELECT 4,2,'TABLE_2','COLUMN_2',6789
INSERT INTO A
SELECT 4,3,'TABLE_2','COLUMN_3',67890
Your Query will return both 2 and 4.
But actually the expected return is "2", as...