Re: Query problem

Hi,

You did not join nodes and nodecoordinates. There is no any join condition in your where clause. It is cartesian product. Your DBA will kill you if you try this query on production system.

Andrew Protasov

> Hi,
>
>
> I make a query on my database that returns the expected result, except
> that some value are duplicated (although the row is unique).
> e.g.:
> name x y card
> -------------------------------- ----------- ----------- -------------------
> -------------
> Berkshire 48 160 C1
> Berkshire 48 160 C2
> Cape 48 160 C3
> Cape 48 160 C4
>
> How can I get only the 2 rows that differ by their names (that is, Berkshire
> and Cape)?? That is, some way to say: "no duplicates in name".
> e.g.:
> name x y
> -------------------------------- ----------- -----------
> Berkshire 48 160
> Cape 48 160
>
> my query looks like this:
> select nodes.name,x,y from nodes, nodecoordinates where mapview=2
>
> any ideas?
>
>
> Thanks!!
> Matt
>
>
>
>
Received on Fri Nov 06 1998 - 00:00:00 CST