SQL Server/T-SQL/Store Procedure Function/Create Function
Содержание
Define function to get last name
14>
15> CREATE FUNCTION fnName (@Name VarChar(100))
16> RETURNS VarChar(100)
17> AS
18> BEGIN
19> DECLARE @CommaPosition Int, @LastName varchar(100)
20> SET @CommaPosition = 6
21> SET @LastName = SUBSTRING(@Name, 1, @CommaPosition)
22> RETURN @LastName
23> END
24> GO
Msg 2714, Level 16, State 3, Server sqle\SQLEXPRESS, Procedure fnName, Line 22
There is already an object named "fnName" in the database.
1>
2> SELECT dbo.fnName("Washington, George")
3> GO
------------------------------------------------------------------------------------------
Washin
(1 rows affected)
1>
2> drop function fnName
3> GO
Define user function and use it in select statement
1>
2> CREATE FUNCTION dbo.ufnIsOdd (@n int)
3> RETURNS bit
4> AS
5> BEGIN
6> RETURN (@n % 2)
7> END
8> GO
1>
2> DECLARE @numb int
3> SET @numb = 6
4> SELECT @numb "Number", dbo.ufnIsOdd (@numb) "Is_odd = 1"
5> SET @numb = 7
6> SELECT @numb "Number", dbo.ufnIsOdd (@numb) "Is_odd = 1"
7>
8> GO
Number Is_odd = 1
----------- ----------
6 0
(1 rows affected)
Number Is_odd = 1
----------- ----------
7 1
(1 rows affected)
1>
Inline Table-Valued Functions
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> -- Inline Table-Valued Functions
3>
4> CREATE FUNCTION myProc(@ID Int)
5> RETURNS Table
6> AS
7> RETURN
8> (
9> SELECT ID, Name, Salary FROM Employee
10> WHERE ID = @ID
11> )
12> GO
1> SELECT * FROM myProc(1)
2> GO
ID Name Salary
----------- ---------- -----------
1 Jason 40420
(1 rows affected)
1>
2> drop table employee
3> GO
1>
Multi-Statement Table-Valued Functions
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> -- Multi-Statement Table-Valued Functions
3>
4> CREATE FUNCTION myProc (@ID Int)
5> RETURNS @EmployeeList Table
6> ( ID Int
7> , Name nVarChar(50)
8> , Salary Money
9> )
10> AS
11> BEGIN
12> IF @ID IS NULL
13> BEGIN
14> INSERT INTO @EmployeeList (ID, Name, Salary)
15> SELECT ID, Name, Salary
16> FROM Employee
17> END
18> ELSE
19> BEGIN
20> INSERT INTO @EmployeeList (ID, Name, Salary)
21> SELECT ID, Name, Salary
22> FROM Employee
23> WHERE ID = @ID
24> END
25> RETURN
26> END
27> GO
1>
2> select * from myProc(1)
3> GO
ID Name Salary
----------- -------------------------------------------------- ---------------------
1 Jason 40420.0000
(1 rows affected)
1>
2> drop function myProc
3> drop table employee
4> GO
1>