postgresql 实现获取所有表名,字段名,字段类型,注释
获取表名及注释：
select relname as tabname,cast(obj_description(relfilenode,’pg_class’) as varchar) as comment from pg_class c
where relkind = ‘r’ and relname not like ‘pg_%’ and relname not like ‘sql_%’ order by relname
过滤掉分表：
加条件 and relchecks=0 即可
获取字段名、类型、注释、是否为空：
SELECT col_description(a.attrelid,a.attnum) as comment,format_type(a.atttypid,a.atttypmod) as type,a.attname as name, a.attnotnull as notnull
FROM pg_class as c,pg_attribute as a where c.relname = ‘表名’ and a.attrelid = c.oid and a.attnum>0
补充：PostgreSQL查询表主键及注释内容
网上关于pgSql获取表主键的内容都是千篇一律，并且对于存在多主键的场景不支持。
附上测试后可获取多个主键字段值的SQL
SELECT
string_agg(DISTINCT t3.attname,’,’) AS primaryKeyColumn
,t4.tablename AS tableName
, string_agg(cast(obj_description(relfilenode,’pg_class’) as varchar),”) as comment
FROM
pg_constraint t1
INNER JOIN pg_class t2 ON t1.conrelid = t2.oid
INNER JOIN pg_attribute t3 ON t3.attrelid = t2.oid AND array_position(t1.conkey,t3.attnum) is not null
INNER JOIN pg_tables t4 on t4.tablename = t2.relname
INNER JOIN pg_index t5 ON t5.indrelid = t2.oid AND t3.attnum = ANY (t5.indkey)
LEFT JOIN pg_description t6 on t6.objoid=t3.attrelid and t6.objsubid=t3.attnum
WHERE t1.contype = ‘p’
AND length(t3.attname) > 0
AND t2.oid = ‘表名’ :: regclass
group by t4.tablename
目前只找到了获取指定表的主键信息，对于批量获取没有找到。
以上为个人经验，希望能给大家一个参考，也希望大家多多支持。如有错误或未考虑完全的地方，望不吝赐教。
