Re: SQL QUERIES ... EXPERT HINTS NEEDED !

"miguel" <jmiguel_at_cet.pt> writes:

>1) Query needed: Given one District (DD=x) , obtain Post Office count,
>and total Population, for all counties (grouped by Counties).
 

>2) Can this be done in a single query ?
 

>I have tried several queries and I usually get the right count of Post
>Offices but I get huge Sums of population. It seems that it keeps adding up
>the population of a same town, for every ocurrence of a Post Office. How
>can I solve this redundancy problem ?

Try this and see if it works:

select cc, count(po_id), sum(pop) from demog, post where demog.tt = post.tt and dd = 'x'
group by cc;

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