SELECT MainTable.Numero FROM MainTable ;
 WHERE MainTable.IGroupe=0 OR MainTable.IGroupe IN ( ;
     SELECT ChildTable.IGroupe FROM ChildTable WHERE ChildTable.No_Membre=7)

>I have a SQL where I am using a UNION. I would like to know if there would be a way to obtain the same without using the UNION.
>
>The SQL is like this:
>
>

>SELECT MainTable.Numero FROM MainTable INNER JOIN ChildTable;
> ON MainTable.IGroupe=ChildTable.IGroupe WHERE ChildTable.No_Membre=7;
> UNION;
>SELECT MainTable.Numero FROM MainTable WHERE MainTable.IGroupe=0
>