pgsql 如何实现用户自定义表结构信息获取

SELECT column_name, data_type, ordinal_position, is_nullable 
FROM information_schema."columns"
WHERE "table_name"='TABLE-NAME' -- 将 'TABLE-NAME' 换成自己的表

SELECT table_name, table_type FROM INFORMATION_SCHEMA.tables WHERE table_schema='public' AND table_type IN ('BASE TABLE','VIEW')

SELECT obj_description(oid, 'pg_constraint') AS d FROM pg_constraint WHERE conname = constraint_name;

-- conname 约束名称
-- contype 约束类型(p:主键, f:外键, c: 检查约束, u:唯一约束)
-- conkey 约束字段
-- confkey 外键字段
-- consrc 检查约束条件
-- confreltable 外键字段引用的表
SELECT conname, contype, conkey, consrc, 
  (SELECT array_agg(column_name::text) FROM INFORMATION_SCHEMA.COLUMNS WHERE ordinal_position = any(conkey) AND table_name= 'TABLE-NAME') AS conkey, 
  (SELECT column_name FROM INFORMATION_SCHEMA.COLUMNS WHERE ordinal_position = any(confkey) AND table_name='TABLE-NAME') AS confkey, 
  (SELECT relname FROM pg_class WHERE oid = confrelid) AS confreltable
FROM pg_constraint WHERE conrelid=(SELECT oid FROM pg_class WHERE relname ='TABLE-NAME'); -- 将 'TABLE-NAME' 换成自己的表

SELECT trigger_name, event_manipulation, event_object_table, action_statement, action_orientation, action_timing FROM INFORMATION_SCHEMA.TRIGGERS;

--table_oid 表的oid
--col_position 字段的位置
SELECT col_description(table_oid, col_position);

select
(select relname as comment from pg_class where oid=a.attrelid) as table_name,
 row_number() over(partition by (select relname as comment from pg_class where oid=a.attrelid) order by a.attnum),
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 '是' else '否' end) as 主键约束,
(case when (select count(*) from pg_constraint where conrelid = a.attrelid and conkey[1]=attnum and contype='u')>0 then '是' else '否' end) as 唯一约束,
(case when (select count(*) from pg_constraint where conrelid = a.attrelid and conkey[1]=attnum and contype='f')>0 then '是' else '否' end) as 外键约束,
(case when a.attnotnull=true then '是' else '否' end) as nullable,
col_description(a.attrelid,a.attnum) as comment
from pg_attribute a
where attstattarget=-1 and attrelid in (select oid from pg_class where relname in(select relname from pg_class where relkind ='r' and relname 
in 
(select tablename from pg_tables where tablename not like 'pg_%' and tablename not like 'sql_%' and schemaname not in(XXXX) and tablename not in(XXXX)
))
order by table_name,a.attnum;