Query IF..ELSE problem

[damgog]

I am new to SQL so please be gentle.
I have three tables A, B and c. I am selecting from a JOIN on these three tables. There are three cases:
if value1 in A > value2 in A
do something, ie. UPDATE tables A, B and C
else if value1 in A = value2 in A
do something else
else if value1 in A < value2 in A
do something else.

Is there any way of writing something like
IF value1 FROM A > value2 FROM A

The closest I can get to that is
IF(SELECT value1 FROM A) > (SELECT value2 FROM A)
This causes an error.

I hope I am making sense. Please dont hesitate to reply if you would like me to clarify the problem

Thank you.

 

[tlbroadbent]

It appears that you'll need to use a cursor. Here is some T-SQL to help you get started.

DECLARE @val1 int, @val2 int
DECLARE TableA_Cursor CURSOR FOR
SELECT value1, value2 FROM TableA

OPEN TabelA_Cursor

FETCH FIRST FROM TabelA_Cursor INTO @val1, @val2
WHILE @@FETCH_STATUS = 0
BEGIN

IF @val1 > @ val2
BEGIN
<Update tables A, B and C>
END
ELSE
IF @val1 = @val2
BEGIN
<do something>
END
ELSE
BEGIN
<Do something>
END

FETCH NEXT FROM TabelA_Cursor INTO @val1, @val2

END

CLOSE TabelA_Cursor
DEALLOCATE TabelA_Cursor

Terry Broadbent
Please review faq183-874.

&quot;The greatest obstacle to discovery is not ignorance -- it is the illusion of knowledge.&quot; - Daniel J Boorstin