SQL Server - FOREIGN KEY - NOCHECK & CHECK CHECK

--drop table dbo.TestDisableFK_Pk

--drop table dbo.TestDisableFK_Fk

create table dbo.TestDisableFK_Pk

(

PKId int not null,

PkStr nvarchar(50) null,

CONSTRAINT [PK_Pk] PRIMARY KEY CLUSTERED 

(

PKId ASC

)

)

create table dbo.TestDisableFK_Fk

(

FKId int not null,

PKId int not null,

PkStr nvarchar(50) null

)

ALTER TABLE dbo.TestDisableFK_Fk  WITH CHECK ADD  CONSTRAINT [FK_Fk] FOREIGN KEY(PKId)

REFERENCES dbo.TestDisableFK_Pk (PKId)

insert into dbo.TestDisableFK_Pk (PKId) values (1), (2), (3)

insert into dbo.TestDisableFK_Fk (FKId, PKId) values (1, 1), (2, 2), (3, 3)

select * from dbo.TestDisableFK_Pk

select * from dbo.TestDisableFK_Fk

update dbo.TestDisableFK_Fk set PKId = 4 where FKId = 1

delete dbo.TestDisableFK_Pk  where PKId = 1

ALTER TABLE dbo.TestDisableFK_Fk NOCHECK CONSTRAINT [FK_Fk]

update dbo.TestDisableFK_Fk set PKId = 4 where FKId = 1

select * from dbo.TestDisableFK_Pk

select * from dbo.TestDisableFK_Fk

ALTER TABLE dbo.TestDisableFK_Fk WITH CHECK CHECK CONSTRAINT [FK_Fk]

update dbo.TestDisableFK_Pk set PKId = 4 where PKId = 1

ALTER TABLE dbo.TestDisableFK_Fk WITH CHECK CHECK CONSTRAINT [FK_Fk]

select * from dbo.TestDisableFK_Pk

select * from dbo.TestDisableFK_Fk