I need a check constraint - sql server

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SimonMeduka asked Aug 7, '13

I need a check constraint - sql server

employee can never be her own manager. I need a constraint on the dbo.Employees to prevent this create dbo.Employees( EmpId INT primary key identity, MgrId INT , FullName NVARCHAR(50)) MgrId for general manager is NULL , REST MANAGER NUMBERS 1,2,3,4 etc ALTER TABLE dbo.Employees ADD CONSTRAINT CK_NULLforGeneralManager CHECK( 'can't figure it out')

sql-server-2012 constraint

10 |1200

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Answer 1 · 2013-08-08T05:51:43Z

Magnus Ahlkvist answered Aug 8, '13

How about this? ALTER TABLE dbo.Employees ADD CONSTRAINT CK_ManagerIsNotSelf CHECK (EmpId MgrId); I would also add a self referencing Foreign Key, to ensure that no Employee has a non existing employee as manager. ALTER TABLE dbo.Employees ADD CONSTRAINT FK_EmployeeManager FOREIGN KEY (MgrId) REFERENCES dbo.Employees(EmpId);

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SimonMeduka commented · Aug 08, 2013 at 10:37 AM

Thank you so much! I am new to sql and looks so easy and simple.

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