更新父表计数在SQL Server更新在子表中的记录

Question

我有两个表

• 部门（DEPTID（PrimaryKey的），DEPTNAME，empcount）
• EmployeeInfo（ empid（primarykey），名称，deptid（foreign_key）参考deptid）

当我在EmployeeInfo中更新deptid记录，立即可以修改计数以适应相应的更改。

子表中的更新将导致父表中的增量和减量。 我知道这可以用一个触发器来完成，但有使用存储过程

Answer 1

我认为这是你在找什么：

CREATE PROCEDURE dbo.UpdateDeptId(
@p_Employee_id int, 
@p_NewDept_id int 
) 
AS 
BEGIN 

UPDATE EmployeeInfo SET deptid = @p_NewDept_id 
WHERE empid = @p_Employee_id 

UPDATE T1 SET T1.EmpCount = T2.CountEmp 
FROM Departments AS T1 INNER JOIN (SELECT deptid , Count(*) as CountEmp FROM EmployeeInfo GROUP BY deptid) AS T2 
ON T1.deptid = T2.deptid 

END 

侧面说明：这是不是最好的做法来存储，总价值IA柱，请尝试使用视图或只是运行一个查询在需要时检索它

Answer 2

恕我直言的方式，总价值应该不是静态列需要更新。

视图会更好。这可以按需点播。

但是，如果你坚持......这是一个选项....不需要具有存储过程的nsync-ness。

-- START TSQL 

SET NOCOUNT ON 


IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLES where TABLE_SCHEMA = N'dbo' and TABLE_NAME = N'Employee' and TABLE_TYPE = N'BASE TABLE') 
BEGIN 
DROP TABLE [dbo].[Employee] 
END 
GO 


IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLES where TABLE_SCHEMA = N'dbo' and TABLE_NAME = N'Department' and TABLE_TYPE = N'BASE TABLE') 
BEGIN 
DROP TABLE [dbo].[Department] 
END 
GO 


DROP FUNCTION dbo.udfEmployeeCountByDepartment 
GO 



CREATE TABLE [dbo].[Department](
    [DepartmentUUID] [uniqueidentifier] NOT NULL, 
    [TheVersionProperty] [timestamp] NOT NULL, 
    [DepartmentName] [nvarchar](80) NULL, 
    [CreateDate] [datetime] NOT NULL, 
    [MyTinyInt] tinyint not null 
    ) 


ALTER TABLE dbo.[Department] ADD CONSTRAINT PK_Department PRIMARY KEY NONCLUSTERED ([DepartmentUUID]) 
GO 

ALTER TABLE [dbo].[Department] ADD CONSTRAINT CK_DepartmentName_Unique UNIQUE ([DepartmentName]) 
GO 






CREATE TABLE [dbo].[Employee] ( 

    [EmployeeUUID] [uniqueidentifier] NOT NULL, 
    [ParentDepartmentUUID] [uniqueidentifier] NOT NULL, 
    [TheVersionProperty] [timestamp] NOT NULL, 
    [SSN] [nvarchar](11) NOT NULL, 
    [LastName] [varchar](64) NOT NULL, 
    [FirstName] [varchar](64) NOT NULL, 
    [CreateDate] [datetime] NOT NULL, 
    [HireDate] [datetime] NOT NULL 
    ) 

GO 

ALTER TABLE dbo.Employee ADD CONSTRAINT PK_Employee PRIMARY KEY NONCLUSTERED (EmployeeUUID) 
GO 


ALTER TABLE [dbo].[Employee] ADD CONSTRAINT CK_SSN_Unique UNIQUE (SSN) 
GO 

ALTER TABLE [dbo].[Employee] ADD CONSTRAINT FK_EmployeeToDepartment FOREIGN KEY (ParentDepartmentUUID) REFERENCES dbo.Department (DepartmentUUID) 
GO 

CREATE FUNCTION dbo.udfEmployeeCountByDepartment(@DepartmentUUID uniqueidentifier) 
RETURNS int 
AS 
BEGIN 
    DECLARE @returnCount int 
    select @returnCount = count(*) from dbo.Employee e where e.ParentDepartmentUUID = @DepartmentUUID 
    RETURN @returnCount 
END 

GO 



ALTER TABLE [dbo].[Department] ADD [ComputedEmployeeCount] as (dbo.udfEmployeeCountByDepartment(DepartmentUUID)) 

GO 



Select * from dbo.Department 

INSERT [dbo].[Department] (DepartmentUUID , DepartmentName , CreateDate) 
Select NEWID() , 'DepartmentOne', CURRENT_TIMESTAMP 
UNION ALL Select NEWID() , 'DepartmentTwo', CURRENT_TIMESTAMP 
UNION ALL Select NEWID() , 'DepartmentThree', CURRENT_TIMESTAMP 
UNION ALL Select NEWID() , 'DepartmentFour', CURRENT_TIMESTAMP 



INSERT INTO [dbo].[Employee] ( 
    [EmployeeUUID] , 
    [ParentDepartmentUUID] , 
    [SSN] , 
    [LastName] , 
    [FirstName] , 
    [CreateDate], 
    [HireDate] 
    ) 
SELECT NEWID() , (select top 1 DepartmentUUID from dbo.Department order by newid()), '111-11-1111', 'OneLN', 'OneFN', CURRENT_TIMESTAMP, CURRENT_TIMESTAMP 
UNION ALL SELECT NEWID() , (select top 1 DepartmentUUID from dbo.Department order by newid()), '222-22-2222', 'TwoLN', 'TwoFN', CURRENT_TIMESTAMP, CURRENT_TIMESTAMP 
UNION ALL SELECT NEWID() , (select top 1 DepartmentUUID from dbo.Department order by newid()), '333-33-3333', 'ThreeLN', 'ThreeFN', CURRENT_TIMESTAMP, CURRENT_TIMESTAMP 
UNION ALL SELECT NEWID() , (select top 1 DepartmentUUID from dbo.Department order by newid()), '444-44-4444', 'FourLN', 'FourFN', CURRENT_TIMESTAMP, CURRENT_TIMESTAMP 
UNION ALL SELECT NEWID() , (select top 1 DepartmentUUID from dbo.Department order by newid()), '555-55-5555', 'FiveLN', 'FiveFN', CURRENT_TIMESTAMP, CURRENT_TIMESTAMP 
UNION ALL SELECT NEWID() , (select top 1 DepartmentUUID from dbo.Department order by newid()), '666-66-6666', 'SixLN', 'SixFN', CURRENT_TIMESTAMP, CURRENT_TIMESTAMP 
UNION ALL SELECT NEWID() , (select top 1 DepartmentUUID from dbo.Department order by newid()), '777-77-7777', 'SevenLN', 'SevenFN', CURRENT_TIMESTAMP, CURRENT_TIMESTAMP 
UNION ALL SELECT NEWID() , (select top 1 DepartmentUUID from dbo.Department order by newid()), '888-88-8888', 'EightLN', 'EightFN', CURRENT_TIMESTAMP, CURRENT_TIMESTAMP 
UNION ALL SELECT NEWID() , (select top 1 DepartmentUUID from dbo.Department order by newid()), '999-99-9999', 'NineLN', 'NineFN', CURRENT_TIMESTAMP, CURRENT_TIMESTAMP 


Select * from dbo.Department