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推荐：sql server function

一、.返回数值的用户自定义函数（标量函数） create function 函数名称 ( 参数1 类型定义1, 参数2 类型定义2, ... ) returns 返回值类型 with encryption as

Prepare data:

USE AdventureWorks2008
GO

CREATE TABLE HumanResources.Employee2
(
  EmployeeID int NOT NULL,
  ManagerID int NULL REFERENCES HumanResources.Employee2(EmployeeID),
  JobTitle nvarchar(50) NOT NULL,
  LastName nvarchar(50) NOT NULL,
  FirstName nvarchar(50) NOT NULL,
    CONSTRAINT PK_Employee2_EmployeeID PRIMARY KEY CLUSTERED (EmployeeID ASC)
);

INSERT INTO HumanResources.Employee2(EmployeeID,ManagerID,JobTitle,LastName,FirstName)
VALUES
  (1, NULL, 'CEO','Smith', 'Hunter'),
  (2, 1, 'CFO', 'Jones', 'Drew'),
  (3, 1, 'COO','Lenzy','Sheila'),
  (4, 1, 'CTO', 'Huntington', 'Karla'),
  (5, 4, 'VP of Engineering', 'Gutierrez', 'Ron'),
  (8, 5, 'VP of Engineering', 'Gutierrez', 'Ron'),
  (9, 5, 'Software Engineer', 'Bray', 'Marky'),
  (10 ,5, 'Data Architect', 'Cheechov', 'Robert'),
  (11 ,5, 'Software Engineer', 'Gale', 'Sue'),
  (6, 4, 'VP of Professional Services', 'Cross', 'Gary'),
  (7, 4, 'VP of Security','Lebowski','Jeff');

Define the function

USE AdventureWorks2008
GO

create function dbo.getManagedEmployee(@managerId int)
returns @employees table(
employeeId int,
managerId int
)
as
begin
insert @employees
select EmployeeID, ManagerID from HumanResources.Employee2 where managerid=@managerId

declare @current int
select @current=min(employeeid) from @employees where managerid=@managerid

while @current is not null
begin
insert @employees select * from getManagedEmployee(@current)
select @current=min(employeeid) from @employees where managerid=@managerid and employeeid>@current
end 
return
end

推荐：SQL Server Isolation Levels By Example

To check the current database isolation level, use:   DBCC useroptions     http://www.gavindraper.co.uk/2012/02/18/sql-server-isolation-levels-by-exam

Call the function:

USE AdventureWorks2008
select * from getManagedEmployee(4)

推荐：SQL Server 2008 function types in T-SQL

SQL Server 2008 function types in T-SQL from： http://searchsqlserver.techtarget.com/generic/0,295582,sid87_gci1327000,00.html   15 Oct 2008 | SearchS