SQL Server/T-SQL/View/SCHEMABINDING

Create function with SCHEMABINDING option

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", 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> CREATE FUNCTION dbo.AverageSalary()
3> RETURNS money
4> WITH SCHEMABINDING
5> AS
6> BEGIN
7>    RETURN (SELECT AVG(salary) FROM dbo.Employee)
8> END
9> GO
1>
2> CREATE FUNCTION dbo.SalaryDifference(@Salary money)
3> RETURNS money
4> AS
5> BEGIN
6>    RETURN @Salary - dbo.AverageSalary()
7> END
8> GO
1>
2> SELECT name,Salary,
3>    dbo.AverageSalary() AS Average,
4>    dbo.SalaryDifference(Salary) AS Difference
5> FROM Employee
6> GO
name       Salary      Average               Difference
---------- ----------- --------------------- ---------------------
Jason            40420            49580.0000            -9160.0000
Robert           14420            49580.0000           -35160.0000
Celia            24020            49580.0000           -25560.0000
Linda            40620            49580.0000            -8960.0000
David            80026            49580.0000            30446.0000
James            70060            49580.0000            20480.0000
Alison           90620            49580.0000            41040.0000
Chris            26020            49580.0000           -23560.0000
Mary             60020            49580.0000            10440.0000
(9 rows affected)
1>
2> drop function dbo.SalaryDifference
3> drop function dbo.AverageSalary
4> GO
1>
2> drop table employee
3> GO
1>