Replace the 1 in the case with area like the msi77 said
From: pgsql-sql-ow...@postgresql.org [mailto:pgsql-sql-ow...@postgresql.org] On Behalf Of David Johnston Sent: Monday, August 15, 2011 9:08 AM To: 'Andreas Forø Tollefsen'; pgsql-sql@postgresql.org Subject: Re: [SQL] Calculate the ratio 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-ow...@postgresql.org [mailto:pgsql-sql-ow...@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). Structure: 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. Any suggestions? Thanks. A.
