SELECT cols,
SUM( CASE WHEN cf = 1 THEN 1 ELSE 0 END ) AS sum_1,
SUM ( CASE WHEN cf = 0 THEN 1 ELSE 0 END ) AS sum_0
FROM table
WHERE cf IN (0, 1)
GROUP BY cols
From: pgsql-sql-owner@postgresql.org [mailto:pgsql-sql-owner@postgresql.org] On Behalf Of Andreas Forø Tollefsen
Sent: Monday, August 15, 2011 8:22 AM
To: pgsql-sql@postgresql.org
Subject: [SQL] Calculate the ratio
Hi all,
This is probably quite simple. I want to calculate the ratio of each country (gwcode) which experiences a 1 in one column (cf).
gid; gridyear; gwcode; area; cf
I want to select the SUM(area) WHERE cf = 1 into one column, and SUM(area) WHERE cf = 0 into another column and group by gridyear and gwcode.
Then i can see the ratio of the area of each country affected by cf.
