Null
September 13, 1998
A final
WHERE clause operator is the
IS NULL/IS NOT NULL operator. This operator is used to test
whether or not a column has a value or not. For example,
we can grab all the columns from the
EMPLOYEES table that have
employee numbers using the following command.
SELECT EMP_NAME, EMP_NUM
FROM EMPLOYEES
WHERE EMP_NUM IS NOT NULL;
In response, you would get:
EMP_NAME EMP_NUM
-------------------------------
Lim Li Chuen 001
Lim Sing Yuen 002
Loo Soon Keat 003
-------------------------------
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