SQL IS NULL Keyword
The IS NULL condition is used to check whether a column contains a NULL value. This is useful when identifying records that are missing data in certain fields.
SQL IS NULL Syntax
SELECT column1, column2, ... FROM table_name WHERE column_name IS NULL;
SQL IS NULL Patients with No dob Example
This query returns all patients who don’t have a birth date (dob
) recorded:
SELECT patient_id, first_name, last_name FROM Patients WHERE dob IS NULL;
