Adding a constraint to table

Eiolon · #1 (**permalink**) 11-17-07, 10:03

Is it possible to add a constraint to a table once it has already been created?

Here is my table:

Code:

id int not null primary key auto_increment,
first_name varchar(25) not null,
last_name varchar(25) not null,
job_id int,
department_id int,
supervisor_id int

I want to add a recursive constraint that references the supervisor_id to the id column.

I tried:

Code:

alter table employees add constraint super_emp foreign key (supervisor_id) references id;

I get an error 1005 saying that I can't create a table.

Thanks for your help.

shammat · #2 (**permalink**) 11-17-07, 11:35

You forgot to mention the referenced table in your alter table statement:

Code:

alter table employees 
  add constraint super_emp foreign key (supervisor_id) 
  references employees(id);

Eiolon · #3 (**permalink**) 11-17-07, 11:41

Figures I'd do something stupid like that. Thanks

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