On Mon, Sep 12, 2011 at 6:48 PM, Phoenix Kiula wrote:
> I have a column in my table:
> user_id varchar(100) ;
>
> This can be NULL, or it can have a value. If it has a value during
> INSERT or UPDATE, I want to check that the user exists against my
> "Users" table. Otherwise, NULL is ok. (Bec
hi, fks do just that.
you can create your fk with just one command:
alter table xxx add constraint fk_name foreign key (user_id) references
users (id);
parent table's id field should also be of the same type and also it should
be primary key or at least unique.
you can create your pk with (if you
Hi,
I bet this is a simple solution but I have been racking my brains.
I have a column in my table:
user_id varchar(100) ;
This can be NULL, or it can have a value. If it has a value during
INSERT or UPDATE, I want to check that the user exists against my
"Users" table. Otherwise, NULL is
