thanks to all for the solutions. I am not sure to have understood the Igor's solution
...SUM(stats.quantity * (stats.which_month = 1)) AS gen.... which is the meaning of the operator * in the statement? regards and still thanks beppe On Sat, Dec 21, 2013 at 8:21 PM, James K. Lowden <jklow...@schemamania.org>wrote: > On Sat, 21 Dec 2013 17:30:50 +0200 > RSmith <rsm...@rsweb.co.za> wrote: > > > Just move the scope of the grouping and use Nulls in stead of 0's, > > like this: > > > > SELECT stats.which_year AS year, > > SUM(CASE WHEN stats.which_month = 1 THEN stats.quantity ELSE NULL > > END) AS gen, > > ELSE NULL is the default > > sqlite> create table T ( t int not null primary key ); > sqlite> insert into T values (1) ; > sqlite> insert into T values (2) ; > sqlite> .nullvalue NULL > sqlite> select t, case t when 1 then 'one' end as tee from T; > 1|one > 2|NULL > > But I would recommend ELSE 0, on the principle that NULL arithmetic is > dodgy at best. > > BTW, "which_month" means the same as "month"; you could tack > "which" in front of any name without changing the meaning. > > --jkl > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
