NULL VALUES and NULL FUNCTIONS in SQL:- In this article, If we do not fill any data in any field if it is not required or we can say that if that field is optional then by default, a table column hold NULL value. You know that NULL value means 0 (Zero), Empty cell, empty, missing, or unknown data.
SELECT Id, Name FROM Student WHERE Address IS NULL
SELECT Id, Name FROM Student WHERE Address IS NOT NULL
We can also use IFNULL(), and COALESCE(), NVL() functions to find IS NULL or NOT NULL VALUES.
SELECT Name, Uinfo*(Admission+ISNULL(New_student,0)) FROM tbl_University