//查询表名称
SELECT tablename FROM pg_tables
WHERE tablename NOT LIKE 'pg%'
AND tablename NOT LIKE 'sql_%'
ORDER BY tablename;
//查询数据库名称
SELECT datname FROM pg_database;
//给表列增加注释
comment on table user is 'Our session logs';
//postgresql查询注释信息
select description from pg_description
join pg_class on pg_description.objoid = pg_class.oid
where relname = 'user'