Where value 'IS NULL' : Where « Select Query « SQL Server / T-SQL






  1. SQL Server / T-SQL
  2. Select Query
  3. Where

Where value 'IS NULL'

1> create table employee(
2>     ID          int,
3>     name        nvarchar (10),
4>     salary      int,
5>     start_date  datetime,
6>     city        nvarchar (10),
7>     region      char (1))
8> GO
1>
2> insert into employee (ID, name,    salary, start_date, city,       region)
3>               values (1,  'Jason', 40420,  '02/01/94', 'New York', 'W')
4> GO

(1 rows affected)
1> insert into employee (ID, name,    salary, start_date, city,       region)
2>               values (2,  'Robert',14420,  '01/02/95', 'Vancouver','N')
3> GO

(1 rows affected)
1> insert into employee (ID, name,    salary, start_date, city,       region)
2>               values (3,  'Celia', 24020,  '12/03/96', 'Toronto',  'W')
3> GO

(1 rows affected)
1> insert into employee (ID, name,    salary, start_date, city,       region)
2>               values (4,  'Linda', 40620,  '11/04/97', 'New York', 'N')
3> GO

(1 rows affected)
1> insert into employee (ID, name,    salary, start_date, city,       region)
2>               values (5,  'David', 80026,  '10/05/98', 'Vancouver','W')
3> GO

(1 rows affected)
1> insert into employee (ID, name,    salary, start_date, city,       region)
2>               values (6,  'James', 70060,  '09/06/99', 'Toronto',  'N')
3> GO

(1 rows affected)
1> insert into employee (ID, name,    salary, start_date, city,       region)
2>               values (7,  'Alison',90620,  '08/07/00', 'New York', 'W')
3> GO

(1 rows affected)
1> insert into employee (ID, name,    salary, start_date, city,       region)
2>               values (8,  'Chris', NULL ,  '07/08/01', 'Vancouver','N')
3> GO

(1 rows affected)
1> insert into employee (ID, name,    salary, start_date, city,       region)
2>               values (9,  'Mary',  NULL ,  '06/09/02', 'Toronto',  'W')
3> GO

(1 rows affected)
1>
2> select * from employee
3> GO
ID          name       salary      start_date              city       region
----------- ---------- ----------- ----------------------- ---------- ------
          1 Jason            40420 1994-02-01 00:00:00.000 New York   W
          2 Robert           14420 1995-01-02 00:00:00.000 Vancouver  N
          3 Celia            24020 1996-12-03 00:00:00.000 Toronto    W
          4 Linda            40620 1997-11-04 00:00:00.000 New York   N
          5 David            80026 1998-10-05 00:00:00.000 Vancouver  W
          6 James            70060 1999-09-06 00:00:00.000 Toronto    N
          7 Alison           90620 2000-08-07 00:00:00.000 New York   W
          8 Chris             NULL 2001-07-08 00:00:00.000 Vancouver  N
          9 Mary              NULL 2002-06-09 00:00:00.000 Toronto    W

(9 rows affected)
1>
2> SELECT *
3> FROM Employee
4> WHERE Salary IS NULL
5> GO
ID          name       salary      start_date              city       region
----------- ---------- ----------- ----------------------- ---------- ------
          8 Chris             NULL 2001-07-08 00:00:00.000 Vancouver  N
          9 Mary              NULL 2002-06-09 00:00:00.000 Toronto    W

(2 rows affected)
1>
2>
3>
4> drop table employee
5> GO
1>








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