how to determint wether two column equals

question:

How to determint  wether two column equals?

Answer:

　　Table one:RecordId = 1,CommonId = 5,Approved = 1.

　　　　　　　RecordId = 2,CommonId = 5 Approved = 0.　　

Table two:RecordId = 4,CommonId = 9,Approved = 1.

　　case one:if you are compare  in the one table.

　　you can use the following code

select commonId,
       (case when max(Approved) = min(Approved) then  else  end) as IsEqual
from MyTable A
group by commonId;

case two:if you are compare in the two tables.

you can use the following code.

SELECT
    CASE
        WHEN (A.Approved = B.Approved) THEN
        ELSE
    END
FROM MyTable A,
MyTable B
WHERE A.commonId = B.commonId;     
Note:you need modify condition A.Approved = B.Approved only ,in compare two tables different column.