Question

我有以下3个表，我试图将模式更改为[Check] .FromCompanyID，[Check] .ToCompanyID和[ActivityToCheck] .ActivityID的唯一性。除了将两个FromCompanyID和ToCompanyID添加到[ActivityToCheck]表之外，我怎样才能修改模式，以便在其中一个表上添加唯一约束？

    CREATE TABLE [dbo].[Activity](
    [ActivityID] [int] IDENTITY(1,1) NOT NULL,
    [UserID] [int] NOT NULL,
    [StartDate] [date] NOT NULL,
    [EndDate] [date] NOT NULL,
    [Description] [nvarchar](255) NULL
    --<OTHER COLUMNS>
)

CREATE TABLE [dbo].[Check](
    [CheckID] [int] IDENTITY(1,1) NOT NULL,
    [CheckNumber] [nvarchar](255) NOT NULL,
    [CheckDate] [date] NOT NULL,
    [CheckDescription] [nvarchar](255) NULL,
    [FromCompanyID] [int] NOT NULL,
    [ToCompanyID] [int] NOT NULL
    --<OTHER COLUMNS>
)

CREATE TABLE [dbo].[ActivityToCheck](
    [ActivityToCheckID] [int] IDENTITY(1,1) NOT NULL,
    [ActivityID] [int] NOT NULL,
    [CheckID] [int] NOT NULL
)

编辑：架构绑定视图是否是确保唯一性的合理方式：

CREATE VIEW TestView 
WITH SCHEMABINDING AS 
SELECT ActivityToCheckID, CheckNumber, CheckID, FromCompanyID, ToCompanyID, ActivityID, AmountPaid
FROM [dbo].[Check] c
inner join [dbo].ActivityToCheck a on c.CheckID = a.CheckID
GO

CREATE UNIQUE CLUSTERED INDEX testindex on TestView (FromCompanyID, ToCompanyID, ActivityID)
GO

谢谢，

Answer 1

您必须对dbo.Check表使用以下触发器：

CREATE TRIGGER YourTriggerName ON dbo.[check]
INSTEAD OF INSERT
AS BEGIN
    IF EXISTS(SELECT *
                FROM Inserted i
                INNER JOIN dbo.ActivityToCheck a1 ON i.CheckId = a1.CheckId
                INNER JOIN dbo.ActivityToCheck a2 ON a2.ActivityId = a1.ActivityId
                INNER JOIN dbo.[CHECK] c ON c.CheckId = a2.CheckId AND c.FromCompanyId=i.FromCompanyId AND c.ToCompanyId=i.ToCompanyId) BEGIN
            RAISERROR('Your information is duplicate.',16,1)
            RETURN;
    End

    INSERT INTO dbo.[check] (CheckNumber, CheckDate, CheckDescription, FROMCompanyId, ToCompanyId)
    SELECT CheckNumber, CheckDate, CheckDescription, FROMCompanyId, ToCompanyId
    FROM Inserted

END

如果FromCompanyId或ToCompanyId可编辑且可以更改，则必须为dbo.Check表创建而不是更新触发器。

MSSQL架构更改以考虑两个表的唯一性

1 个答案: