Question

I just need some in help to implement delete cascade in my stored procedure because I have REFERENCE constraint error

Create PROCEDURE [dbo].[DeleteProject]
    @ProjectID uniqueidentifier
AS
BEGIN
    -- Insert statements for procedure here
    DELETE FROM [TaskManagementSystem_DB].[dbo].[Projects]
    WHERE projectID = @ProjectID
END

Answer 1

You don’t implement delete cascade in the proc.

You either implement delete cascase on the foriegn key constraint itself:

ALTER TABLE [ChildTable] WITH CHECK ADD CONSTRAINT [FK_ChildTable_Projects] FOREIGN KEY ([ProjectID})
REFERENCES [Project] ([ProjectID])
ON DELETE CASCADE

or you need to explicitly delete the child record before you delete the master.

Create PROCEDURE [dbo].[DeleteProject]
@ProjectID uniqueidentifier
AS
BEGIN

DELETE child
FROM [TaskManagementSystem_DB].[dbo].[Projects] proj
    JOIN [TaskManagementSystem_DB].[dbo].[ChildTable] child
        ON proj.ProjectID = child.ProjectID

DELETE FROM [TaskManagementSystem_DB].[dbo].[Projects]
    WHERE projectID = @ProjectID

END