项目用了Postgresql 数据库，项目组要出表结构的文档，手写太麻烦，想用slq脚本导出一份。查了一番资料，似乎没有多好的方法。dump方式导出的脚本太乱，没法直接写在word文档里。只能自己写sql查询出表结构，然后利用pgadmin的导出查询结果的功能，能最快的获取一份整个数据库的表结构信息。虽然不能实现全自动的导出文档，但是对整理文档来说，还是节省了不少时间。
--查询所有的表字段信息(带表名)
select
(select relname||'--'||(select description from pg_description where objoid=oid and objsubid=0) as comment from pg_class where oid=a.attrelid) as table_name,
a.attname as column_name,
format_type(a.atttypid,a.atttypmod) as data_type,
(case when atttypmod-4>0 then atttypmod-4 else 0 end)data_length,
(case when (select count(*) from pg_constraint where conrelid = a.attrelid and conkey[1]=attnum and contype='p')>0 then 'Y' else 'N' end) as 主键约束,
(case when (select count(*) from pg_constraint where conrelid = a.attrelid and conke
