添加外键时SQL Server中的错误

Question

There are no primary or candidate keys in the referenced table 'Employee' that match the referencing column list in the foreign key.

I have already set my reference as primary key, but still getting the error.

 Create table Employee 
 (
     Fname varchar(20),
     Mint varchar(1),
     Lname varchar(20),
     Ssn int,
     Bdat date,
     [Address] varchar(50),
     Sex varchar(1),
     Salary int,
     Super_ssn int,
     Dno int
)

Create table Department   
(
     Dname varchar(20),
     Dnumber int,
     Mgr_ssn int,
     Mgr_start_date date
)

Alter table Employee
alter column Ssn int NOT NULL
alter column Super_ssn int NOT NULL

alter table Employee
add primary key (Ssn, Super_ssn)

alter table Department 
add foreign key (Mgr_ssn) 
    References Employee (Ssn)

Answer 1

You have a composite PK in your Employees table ( Ssn, Super_ssn ), but you try to reference it with one column ( Mgr_ssn ).

Either change the PK to Ssn only, or add another column to the foreign key.