MySQL IS NOT NULL condition is used to check the NOT NULL value in the expression. It is used with SELECT, INSERT, UPDATE and DELETE statements.
expression IS NOT NULL
expression: It specifies a value to test if it is not NULL value.
Consider a table "officers" having the following data.
Execute the following query:
SELECT * FROM officers WHERE officer_name IS NOT NULL;
Note: Here, you are getting the complete "officers" table as result because every value is NOT NULL in the table.