select * from myTable T where c1<>c2 and not exists (select 1 from myTable where c1=c2 and c3 = T.c3)

I haven't read the whole thread yet.

>Hi All,
>
>I have a SQL problem I have no idea if I can solve it with one select (I can do with two, but this is not what i like to have)
>
>The problems comes from an import scenario.
>
>I have a table like
>

>c1   c2  c3 ...
>A    a    1
>A    b    2
>A    b    3
>B    c    4
>B    d    4
>A    b    3
>

>
>For a given c3 the combination of c1 and c2 should be the same. We can see that for c3=4 this is not true.
>
>How do I code a single SELECT SQL that returns just
>
>

>c1   c2  c3
>B    c    4
>B    d    4
>

>
>and
>
>

>c3
>4
>

>
>
>TIA
>
>Agnes