> > Table1:
> > M_id, M_desc, M_desc2,...
>
> So M_ID is Unique PRIMARY_KEY = M_id

Exactly!

> > Table2:
> > MC_id, MC_key, MC_qty,...
> >
> > Each record in Table1 can have multiply records in Table2.
>
> So MC_key may not be unique?

Exactly!

> But MC_id + MC_key is unique ? ( Different MS_id's could have the same
> MC_key ? )

Exactly!
Pretty basic stuff, as you see.

> > Now I had M_id in Table1 as primary key, and MC_id and MC_key
> from Table2 as
> > primary key. MC_id is equal to M_id, and MC_id and MC_key is a
> unique pair.
> >
> > Could you explain me, how should I proper do this relationship.
>
> Table2 PRIMARY_KEY = ( MC_id, MC_key )

I don't understand the difference in your "PRIMARY_KEY = ( MC_id, MC_key )"
or if I say, that table2 has two primary keys.

> I have records in master table 1 to n
> and sub records in detail table 1(1 to n)
> so the the detail table uses record and subrecord to create a primary
> key. All details will have a sub record of 1, but only one for each
> master record.
> Hope that covers it ;)

In theory I understand it now. Also in praxis it works in my project. But
I'm still not sure, if I'm doing it the right way, so I'll put some more
details:

I'm using CB6, and for database creation IBeasy+. I don't create database
tables programatically, since I don't know how to (yet).

I have two datasets, DS1 and DS2. DataSource from DS2 is connected to
DataSource1.

sql in DS1:

select * from TABLE1

sql in DS2:

select * from TABLE2 where MC_ID = :M_ID;

This works fine: I select the record in Table1, and in table2 are all proper
records displayed.

And for example, delete sql in DS2 is following:

delete from TABLE2
where
MC_ID = :OLD_MC_ID and
MC_key = :OLD_MC_key

modify sql in DS2:

update TABLE2
set
MC_ID = :MC_ID,
MC_key = :MC_key,
MC_qty = :MC_qty
where
MC_ID = :OLD_MC_ID and
MC_key = :OLD_MC_key


Is this the "normal" way to create a simple master-detail relationship, or
did I completely missed something.
Can you recommend me some good tutorials on this ?

Regards,
Primoz