Subject Re: [firebird-support] Union statement automatically adds 'DISTINCT'?
Author Dennis McFall
At 04:32 PM 4/30/2007, you wrote:
>I have two statements:
>Select [fields] from [Table1]
>Select [fields] from [Table2]
>The [Fields] are the same. Running them individually I get 39 records,
>and 1 record. Running them together with a UNION between them I get 33
>records. After some checking, it appears that what it thinks are
>duplicates are being removed. I never specified the DISTINCT option for
>the select statement though. Can anyone confirm that this is what
>Firebord does?

My experience confirms yours. (FB 1.5). I found that I had to add
another, otherwise immaterial, field to the selects in a UNION
select (to distinguish two otherwise identical records), or I would
not get all of the records I wanted. I don't know what the
relational algebraic theory is....