Unique constraint for the columns does not work when one of values is null.

I have a table with a unique constraint on two integer columns.
Works fine, but one of the two columns can be null and then the
constraint does not work.
1 2 : OK
1 3 : OK
1 2 : error
2 null : OK
2 null : OK -> I want this to result in an error

Pugi!

Re: Unique constraint for the columns does not work when one of values is null.

On 14 Sep, 11:55, Pugi! wrote:
> I have a table with a unique constraint on two integer columns.
> Works fine, but one of the two columns can be null and then the
> constraint does not work.
> 1 2 : OK
> 1 3 : OK
> 1 2 : error
> 2 null : OK
> 2 null : OK -> I want this to result in an error
>
> Pugi!

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