> >>Violation of PRIMARY or UNIQUE KEY constraints "INTEG_94" on table
> >>"MATCONTI"
> >
> > Maybe I should tell before, that both MC_MAT_KEY and MC_MAT_KC
> are primary keys.

Thanks Lester for your answer.

> If just the combination should be unique then the PRIMARY KEY should
> contain both, but if MC_MAT_KEY is a generator, the it will always be
> unique, so just drop MC_MAT_KC from the primary key.

The combination of both should be unique. There is no generator in this
table.
I don't know, if I understand it now:
I tought, that if the table has two primary keys, there should be a unique
combination.

What did you mean with "PRIMARY KEY should contain both" ?

Regards,
Primoz