Looking for NOT NULL value

In every row, there can be NULL values, i.e. fields with unknown missing values. Remember the Opel from our table with its missing price? This is exactly a NULL value. We simply don't know the price.

To check whether a column has a value, we use a special instruction IS NOT NULL.

SELECT id
FROM user
WHERE middle_name IS NOT NULL;

This code selects only those users who have a middle name, i.e. their column middle_name is known.



Syntax
SELECT * FROM table_name WHERE column_name IS NOT NULL;

Exercise

Select all cars whose price column isn't a null value.

SELECT * FROM car WHERE price IS NOT NULL;

VIN	BRAND	MODEL	PRICE	PRODUCTION_YEAR
LJCPCBLCX14500264	Ford	Focus	8000.00	2005
WPOZZZ79ZTS372128	Ford	Fusion	12500.00	2008
JF1BR93D7BG498281	Toyota	Avensis	11300.00	1999
KLATF08Y1VB363636	Volkswagen	Golf	3270.00	1992
1M8GDM9AXKP042788	Volkswagen	Golf	13000.00	2010
1HGCM82633A004352	Volkswagen	Jetta	6420.00	2003
1G1YZ23J9P5800003	Fiat	Punto	5700.00	1999