NOT EXISTS in Teradata

NOT EXISTS checks the non-existence of records in the target table.
If the records are not present, then NOT EXISTS will be evaluated true otherwise we can say that the NOT EXISTS condition is considered "to be met" if the sub query returns no rows.

Syntax:
SELECT columns
FROM tables
WHERE NOT EXISTS ( subquery );


Example:
SELECT *
FROM suppliers
WHERE NOT EXISTS
(select * from orders where suppliers.supplier_id = orders.supplier_id);

This will return all records from the suppliers table where there are no records in the orders table for the given supplier_id.