On 2009-01-27, Alban Hertroys <dalroi@solfertje.student.utwente.nl> wrote:
> On Jan 25, 2009, at 3:07 AM, Jasen Betts wrote:
>
>>> I want to use this column as a foreign key on a column in another
>>> table
>>> (column 2), but cannot without a full unique index.
>>
>> a full unique index is easy use an expression that's null for -1.
>>
>> create unique index foobar on foo( ( case fee when -1 then null else
>> fee end ) );
>
>
> anything wrong with create unique index foobar on foo where fee <> -1 ?
neither way works for a foreign key.
easiest solution seems to be to insert a record matching -1 in the
other table (with all other fields null)