sql: check if entry in table A exists in table B

SELECT *
FROM   B
WHERE  NOT EXISTS (SELECT 1 
                   FROM   A 
                   WHERE  A.ID = B.ID)

The classical answer that works in almost every environment is

SELECT ID, Name, blah, blah
FROM TableB TB
LEFT JOIN TableA TA
ON TB.ID=TA.ID
WHERE TA.ID IS NULL

sometimes NOT EXISTS may be not implemented (not working).

If you are set on using EXISTS you can use the below in SQL Server:

SELECT * FROM TableB as b
WHERE NOT EXISTS
(
   SELECT * FROM TableA as a
   WHERE b.id = a.id
)

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