Jeden zapeklity SQL dotaz

[Roman LISZKA]

Radim Kubacki wrote:
> 
> Zeby takhle?
> 
> select Osnova.IDUcet,
>     sum(MD.Cena)/count(distinct DAL.rowid) as MDSuma,
>     sum(DAL.Cena)/count(distinct MD.rowid) as DalSuma
> from Osnova
>     left outer join PDenik MD on Osnova.IDUcet=MD.MDUcet
>     left outer join PDenik DAL on Osnova.IDUcet=Dal.DalUcet
> group by Osnova.IDUcet
> Prave proto, aby se to nezapocitavalo vicekrat. Misto rowid by sel pouzit i
> nejaky klic z PDenik.

Mozna ano, ale kdyz dojde k deleni nulou, neni ve vysledku vubec radek s
IDUcet=311. Ale zkusim zkombinovat s uniony.

> Holt SQL ma spoustu much, ktere muze clovek kritizovat. Treba by si to
> clovek predstavoval takto:
> 
> select *
> from
>     (select Osnova.IDUcet, sum(MD.Cena) as MDSuma
>     from Osnova
>     left outer join PDenik MD on Osnova.IDUcet=MD.MDUcet
>     group by Osnova.IDUcet) TMD
>     outer join
>     (select Osnova.IDUcet, sum(MD.Cena) as MDSuma
>     from Osnova
>     left outer join PDenik MD on Osnova.IDUcet=MD.MDUcet
>     group by Osnova.IDUcet) TDAL on TMD.IDUcet = TDAL.IDUcet
> 

To by po uprave slo, ale LocalSQL v BDE od Borlandu nezvlada 
slozeny SELECT. Dik za snahu. 

> Radim

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