sql is not null

1SELECT column_name FROM table_name 
2WHERE column_name IS NOT NULL;

1SELECT column_names
2FROM table_name
3WHERE column_name IS NOT NULL;

1SELECT column_name FROM table_name 
2WHERE column_name IS NULL;

1SELECT * FROM my_table WHERE my_column IS NOT NULL;

1Tests for empty (NULL) values.
2Example: Returns users that haven’t given a contact number.
3SELECT * FROM users
4WHERE contact_number IS NULL;

1The reverse of NULL. Tests for values that aren’t empty / NULL
2"Tests for empty (NULL) values.
3Example: Returns users that haven’t given a contact number.
4SELECT * FROM users
5WHERE contact_number IS NULL;"