Question

I have a TableA

ID  MatCh01 Match02 Status
1    1001    12    
2    1001    12
3    1001    12
4    1002    44
5    1002    47
6    1003    22
7    1003    22
8    1004    55
9    1004    57

I want to populate column = status with “FAIL” when :
For same match01, there exist different match02. Expected TableA :

ID  MatCh01 Match02 Status
1    1001    12      NULL   
2    1001    12      NULL
3    1001    12      NULL
4    1002    44      FAIL
5    1002    47      FAIL
6    1003    22      NULL
7    1003    22      NULL
8    1004    55      FAIL
9    1004    57      FAIL

Please NOTE: FAIL all ‘match01’ if its corresponding ‘match02’ is different.
Thanks

Answer 1

Basically this says Update all Values in TableA when the MAX and MIN of Column Match02 are not equal (meaning match01 has multiple rows with different values for match 02).

UPDATE A
SET Status = 'FAIL'
FROM TableA A
INNER JOIN (SELECT 
              a2.Match01
            FROM TableA A2
            GROUP BY a2.Match01
            HAVING MAX(Match02) <> MIN(Match02)) B ON
  A.Match01 = B.Match01