At 11:49 PM 15/04/2008, you wrote:

>Is there a way to prevent a Insert, if a unique column contains the
>same word which is to insert but only in upper chars ?

Add another column, a varchar of the same size, and place the unique index on it, not on the mixed case column.

Have a Before Insert trigger to populate the "case insensitive" column:

as
if (new.MixedCaseColumn is not null) then
new.CaseInsensitiveColumn = UPPER(new.MixedCaseColumn);

Of course, if MixedCaseColumn is non-nullable, the null test isn't required.

./heLen