--創建主鍵
IF NOT EXISTS (select name from dbo.sysobjects where xtype='PK' and parent_obj=(select id from dbo.sysobjects where name='Employee'))
BEGIN
ALTER TABLE Employee ADD PRIMARY KEY(Id);
END
GO
--創建外鍵
IF NOT EXISTS(SELECT * FROM information_schema.KEY_COLUMN_USAGE WHERE CONSTRAINT_NAME='FK_Employee_Department')
BEGIN
ALTER TABLE [dbo].[Employee] WITH CHECK ADD CONSTRAINT [FK_Employee_Department] FOREIGN KEY([DptID])
REFERENCES [dbo].[Department] ([DptID])
ALTER TABLE [dbo].[Employee] CHECK CONSTRAINT [FK_Employee_Department]
END
GO
--創建非聚集索引
IF NOT EXISTS (SELECT * FROM sys.indexes WHERE name='NonClusteredIndex_Employee_Name')
BEGIN
CREATE INDEX NonClusteredIndex_Employee_Name ON Employee(Name)
END
GO
--添加列
IF NOT EXISTS(SELECT * FROM SYSCOLUMNS WHERE id=OBJECT_ID('Employee') and name='Name')
BEGIN
ALTER TABLE Employee ADD Name VARCHAR(20)
END
GO
--創建觸發器，當語文分數變化時，修改學生的總分數,其中inserted表示語文分數變化的數據行的集合
IF NOT EXISTS(SELECT * FROM SYSOBJECTS WHERE TYPE='tr' and name='Trigger_Student_TotalScore')
BEGIN
EXECUTE ('CREATE TRIGGER [dbo].[Trigger_Student_TotalScore]
ON [dbo].[Student] AFTER UPDATE
AS IF UPDATE(ChineseScore)
BEGIN
UPDATE Student SET TotalScore=ChineseScore+MathScore WHERE ID=(SELECT ID FROM inserted)
END')
END
//創建默認值
IF(SELECT default_object_id FROM sys.columns WHERE object_id = OBJECT_ID('Employee') AND name='UserNo')=0
BEGIN
ALTER TABLE [dbo].[Employee] ADD DEFAULT ((0)) FOR [UserNo]
END
GO
//創建視圖，先刪除再創建可以達到更新的目的
IF EXISTS(SELECT * FROM sys.views WHERE object_id = OBJECT_ID(N'vStudents'))
BEGIN
DROP VIEW [dbo].[vStudents]
END
GO
CREATE view [dbo].[vStudents]
as
SELECT Name,Age FROM Students
GO