sum multiple tables gives wrong answer?

Hi,

I'm new to the list and have the following situation happening "PostgreSQL
8.4.1, compiled by Visual C++ build 1400, 32-bit" running windows XP sp3

I have an SQL problem that I thought was easy to do but gives me always the
wrong answer.

2 Tables with a column called "flaeche" "double precision", in English
"area" and I want to sum up the values for flaeche in each table to give me
the total area for flaeche in each table.

Correct answer comes with this sql

select sum(flaeche)/10000 as "greens HA" from green;

result:

greenHA

1.25358085

Wrong Answer with this query

select

sum(green.flaeche)/10000 as "greens HA",

sum (fairway.flaeche)/10000 as "fairway HA"

from green, fairway;

result:

green HA fairway HA

48.8896531 508.94143659

Fairway correct answer is 14.96886578 HA

Green correct answer is 1.25358085 HA

What is going on ??

Cheers

michael

Michael Diener

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