SQL Server/T-SQL Tutorial/Query/IS NULL

A SELECT statement that retrieves rows with null values

5>
6> create table Billings (
7>     BankerID           INTEGER,
8>     BillingNumber      INTEGER,
9>     BillingDate        datetime,
10>     BillingTotal       INTEGER,
11>     TermsID            INTEGER,
12>     BillingDueDate     datetime ,
13>     PaymentTotal       INTEGER,
14>     CreditTotal        INTEGER
15>
16> );
17> GO
1>
2> INSERT INTO Billings VALUES (1, 1, "2005-01-22", 165, 1,"2005-04-22",123,321);
3> GO
(1 rows affected)
1> INSERT INTO Billings VALUES (2, 2, "2001-02-21", 165, 1,"2002-02-22",123,321);
2> GO
(1 rows affected)
1> INSERT INTO Billings VALUES (3, 3, "2003-05-02", 165, 1,"2005-04-12",123,321);
2> GO
(1 rows affected)
1> INSERT INTO Billings VALUES (4, 4, "1999-03-12", 165, 1,"2005-04-18",123,321);
2> GO
(1 rows affected)
1> INSERT INTO Billings VALUES (5, 5, "2000-04-23", 165, 1,"2005-04-17",123,321);
2> GO
(1 rows affected)
1> INSERT INTO Billings VALUES (6, 6, "2001-06-14", 165, 1,"2005-04-18",123,321);
2> GO
(1 rows affected)
1> INSERT INTO Billings VALUES (7, 7, "2002-07-15", 165, 1,"2005-04-19",123,321);
2> GO
(1 rows affected)
1> INSERT INTO Billings VALUES (8, 8, "2003-08-16", 165, 1,"2005-04-20",123,321);
2> GO
(1 rows affected)
1> INSERT INTO Billings VALUES (9, 9, "2004-09-17", 165, 1,"2005-04-21",123,321);
2> GO
(1 rows affected)
1> INSERT INTO Billings VALUES (0, 0, "2005-10-18", 165, 1,"2005-04-22",123,321);
2> GO
(1 rows affected)
1>
2>
3> SELECT *
4> FROM Billings
5> WHERE BillingTotal IS NULL
6> GO
BankerID    BillingNumber BillingDate             BillingTotal TermsID     BillingDueDate          PaymentTotal CreditTotal
----------- ------------- ----------------------- ------------ ----------- ----------------------- ------------ -----------
(0 rows affected)
1>
2> drop table Billings;
3> GO
1>

IS NULL and = NULL

4>
5> CREATE TABLE titleauthor(
6>    au_id          varchar(20),
7>    title_id       varchar(20),
8>    au_ord         tinyint               NULL,
9>    royaltyper     int                   NULL
10> )
11> GO
1>
2> insert titleauthor values(null, "2", 1, 60)
3> insert titleauthor values("2", "3", 1, 100)
4> insert titleauthor values("3", "4", 1, 100)
5> insert titleauthor values("4", "5", 1, 100)
6> insert titleauthor values("5", "6", 1, 100)
7> insert titleauthor values("6", "7", 2, 40)
8> insert titleauthor values("7", "8", 1, 100)
9> insert titleauthor values("8", "9", 1, 100)
10> GO
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
1>
2> select * from titleauthor where au_id is null;
3> GO
au_id                title_id             au_ord royaltyper
-------------------- -------------------- ------ -----------
NULL                 2                         1          60
(1 rows affected)
1> select * from titleauthor where au_id = null;
2> GO
au_id                title_id             au_ord royaltyper
-------------------- -------------------- ------ -----------
(0 rows affected)

The syntax of the WHERE clause with the IS NULL clause

WHERE expression IS [NOT] NULL
The contents of the NullSample table
SELECT * FROM NullSample