Normalization questions...

Hi,
I am building a generic database editor for webpages... and I am confused. How do you deal with tables without keys?

Ok from start, I have users table, which has uid as primary key for the record, then there is other table, groups with gid as a key in it. In between there is table that has two fields gid and uid, that basically ties two tables, those fields are indexed. However the third table does not have key field. To locate records within database editor I use keys, to locate a specific record. As far as I understand RDBMS theory you should not "UPDATE" items in KEY fields. If I edit the linking record however, there are no unique keys, so it should not be too much of a problem. But it does collide with what I know about databases.

So my main question is, should I expect a user to provide a record ID for each table, even though it might be not needed, in order for it to be editable, or should I just go against my intuition?
Thanks,

        Pavel

-- 
              "They that give up essential liberty to 
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