postgres†
select†
select * from [table] where [colomn] is null;
select * from [table] where [colomn] is not null;
select * from [table] where [colomn] like '%hoge%';
select * from [table] where [colomn] not like '%hoge%';
重複削除†
delete from 【TABLE】 where 【ID】 in
(select 【ID】
from 【TABLE】 S1
where 【ID】< (select MAX(【ID】) from 【table】 as S2 where
S1.key1=S2.key1 and S1.key2=S2.key2 ..... ) ) ;
psql 編†
psql†
psql [-h 【hostname】] -d 【dbname】
backup†
pg_dump 【dbname】 > dbname.dump
psql -d 【dbname】 -f dbname.dump
重複検索†
select min(id) from item group by time having count(*) > 1