SQL Server/T-SQL/Aggregate Functions/COUNT BIG

COUNT_BIG deals with NULL values

1> create table employee(
2>     ID          int,
3>     name        nvarchar (10),
4>     salary      bigint,
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>
3> --.
4> select COUNT_BIG(salary) from employee
5> GO
--------------------
                   7
Warning: Null value is eliminated by an aggregate or other SET operation.
1>
2>
3>
4> drop table employee
5> GO
1>

COUNT_BIG: return value has a data type of bigint

1> create table employee(
2>     ID          int,
3>     name        nvarchar (10),
4>     salary      bigint,
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", 26020,  "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",  60020,  "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                     26020 2001-07-08 00:00:00.000 Vancouver  N
          9 Mary                      60020 2002-06-09 00:00:00.000 Toronto    W
(9 rows affected)
1>
2>
3> --COUNT_BIG: return value has a data type of bigint
4>
5> select COUNT_BIG(DISTINCT salary) from employee
6> GO
--------------------
                   9
(1 rows affected)
1>
2>
3>
4> drop table employee
5> GO
1>