update statement conflicted with foreign key constraint - sql-server

Question

I have problem on updating column set as primary key, even I made on update set default
this is my code for creating tables, I set on update set default
create table department(
id int default 10 primary key,
name varchar(50)
);
create table employee
(
id int primary key,
dept_id int default 40 foreign key references department(id) on update set default on delete set default,
name varchar(40)
);
after that, I inserted data to the tables
insert into department
values
(1,'hr'),
(2,'programming'),
(3,'telesales'),
(4,'database')
insert into employee
values
(1,1,'mohammed'),
(2,2,'magd'),
(3,1,'soha'),
(4,3,'sameh'),
(5,4,'ashraf')
but, when I run this code to update the column id
update department
set id = 44 where id = 4
I get that error
The UPDATE statement conflicted with the FOREIGN KEY constraint "FK__employee__dept_i__571DF1D5". The conflict occurred in database "test", table "dbo.department", column 'id'.
The statement has been terminated.
but I do not know where is my fault!
thanks

Answer 1

Use ON UPDATE CASCADE in the foreign key constraint, like so:
create table employee
(
id int primary key,
dept_id int default 40 foreign key references department(id) on update cascade on delete set default,
name varchar(40)
);
If there is any update to the id column value, dept_id also gets updated to follow the changed value.

Answer 2

Because employee table have dept_id column *constraint* with id column of department. This error is encountered when the primary key of a table is updated but it is referenced by a foreign key from another table and the update specific is set to No action. The No action is the default option.
If this is your case and No action is set on the update operation you can change the foreign-key definition to Cascade
You can try this:
ALTER TABLE employee
DROP Constraint FK__employee__dept_i__571DF1D5
GO
ALTER TABLE employee
ADD CONSTRAINT New_FK_Constraint
FOREIGN KEY (dept_id) REFERENCES department (id)
ON DELETE CASCADE ON UPDATE CASCADE
GO

Answer 3

it's normally to that error to appear, You have a foreign key relation and you then change the value.
Use ON UPDATE CASCADE in the foreign key constraint

Answer 4

If you don't want to change your table structure, you can run the following query:
ALTER TABLE [UserStore]
NOCHECK CONSTRAINT FK_UserStore_User_UserId
ALTER TABLE [UserIdentity]
NOCHECK CONSTRAINT FK_UserIdentity_User_UserId
BEGIN TRAN
UPDATE [user]
SET Id = 10
WHERE Id = 9
UPDATE [dbo].[UserStore]
SET UserId = 10
WHERE UserId = 9
UPDATE [dbo].UserIdentity
SET UserId = 10
WHERE UserId = 9
COMMIT TRAN
ALTER TABLE [UserStore]
CHECK CONSTRAINT FK_UserStore_User_UserId
ALTER TABLE UserIdentity
CHECK CONSTRAINT FK_UserIdentity_User_UserId