PostgreSQL查询数据库表以及每一个表里面的字段的类型，字段名称，字段意思

select relname as tabname,
cast(obj_description(relfilenode,'pg_class') as varchar) as comment from pg_class c 

where relname ='user';

select relname as tabname,cast(obj_description(relfilenode,'pg_class') as varchar) as comment from pg_class c
where relname in (select tablename from pg_tables where schemaname='public' and position('_2' in tablename)=0);

select tablename from pg_tables where
 schemaname='public' and position('_2' in tablename)=0;

select a.attnum,a.attname,concat_ws('',t.typname,SUBSTRING(format_type(a.atttypid,a.atttypmod) from '\(.*\)')) as type,d.description from pg_class c,pg_attribute a,pg_type t,pg_description d
where c.relname='zr_wx_db_sobu_ele' and a.attnum>0 and a.attrelid=c.oid and a.atttypid=t.oid and d.objoid=a.attrelid and d.objsubid=a.attnum;

select c.relname 表名,cast(obj_description(relfilenode,'pg_class') as varchar) 名称,a.attname 字段,d.description 字段备注,concat_ws('',t.typname,SUBSTRING(format_type(a.atttypid,a.atttypmod) from '\(.*\)')) as 列类型 from pg_class c,pg_attribute a,pg_type t,pg_description d
where a.attnum>0 and a.attrelid=c.oid and a.atttypid=t.oid and d.objoid=a.attrelid and d.objsubid=a.attnum
and c.relname in (select tablename from pg_tables where schemaname='public' and position('_2' in tablename)=0) order by c.relname,a.attnum