Using IF EXISTS with a CTE

Question

I want to check if a CTE table has record or null. But I always get error message 'Incorrect syntax near the keyword 'IF'' for the SQL below. Now there is no matching record in ADMISSION_OUTSIDE TABLE. The result of the SQl should print 'NOT OK'. Thanks,

WITH ADMISSION_OUTSIDE AS 
(   .....
.....
)

IF EXISTS (SELECT * FROM ADMISSION_OUTSIDE)
PRINT 'OK'
ELSE PRINT 'NOT OK'

Answer 1

From MSDN

A CTE must be followed by a single SELECT, INSERT, UPDATE, or DELETE statement that references some or all the CTE columns

It can be re-written like this

WITH ADMISSION_OUTSIDE AS 
(   .....
.....
)
SELECT 'OK' WHERE EXISTS (SELECT * FROM ADMISSION_OUTSIDE)
UNION ALL
SELECT 'NOT OK' WHERE NOT EXISTS (SELECT * FROM ADMISSION_OUTSIDE)

Here is a demo

;WITH CTE AS
(
SELECT 1 as a WHERE 1=0
)
SELECT 'OK' WHERE EXISTS (SELECT * FROM CTE)
UNION ALL
SELECT 'NOT OK' WHERE NOT EXISTS (SELECT * FROM CTE)

Result : NOT OK

;WITH CTE AS
(
SELECT 1 as a WHERE 1=1
)
SELECT 'OK' WHERE EXISTS (SELECT * FROM CTE)
UNION ALL
SELECT 'NOT OK' WHERE NOT EXISTS (SELECT * FROM CTE)

Result : OK