Question

是否可以配置检查约束，以便在每次修改时都应用（检查）它？即，无论特定的检查字段是否实际被修改。

CREATE TABLE dbo.SomeTable (
    Id   INT IDENTITY(1, 1) NOT NULL
  , Name NVARCHAR(50)  NOT NULL
  , Who  NVARCHAR(128) NOT NULL
  , CONSTRAINT PK_SomeTable PRIMARY KEY CLUSTERED (Id ASC)
)
GO

ALTER TABLE dbo.SomeTable ADD CONSTRAINT DF_dbo_SomeTable_Who DEFAULT (SUSER_SNAME()) FOR Who;
GO

ALTER TABLE dbo.SomeTable WITH CHECK ADD CONSTRAINT CHK_dbo_SomeTable_WhoEqualsUser CHECK (Who = SUSER_NAME());
GO

INSERT INTO dbo.SomeTable (Name) VALUES (N'SomeBody');


EXECUTE AS USER = N'NotMe';
GO
    UPDATE dbo.SomeTable SET Name = N'SomebodyElse'; -- Want this update-attempt to throw an exception
        -- But it doesn't throw here because the check constraint isn't checked

    UPDATE dbo.SomeTable SET Name = N'SomebodyElse'  -- Don't want this update-attempt to throw
                           , Who = N'NotMe'          -- since Who = SUSER_NAME()
GO
REVERT

如何在每次修改时强制应用检查约束

0 个答案: