Answers for "how to check for a value being not null in sql server"

sql is not null

SELECT * FROM my_table WHERE my_column IS NOT NULL;

find value if not null in sql

SELECT FIRST_NAME , MANAGER_ID 
FROM EMPLOYEES 
WHERE MANAGER_ID IS NOT NULL ;

sql is not null

The reverse of NULL. Tests for values that aren’t empty / NULL
"Tests for empty (NULL) values.
Example: Returns users that haven’t given a contact number.
SELECT * FROM users
WHERE contact_number IS NULL;"