pgsql 實(shí)現(xiàn)用戶自定義表結(jié)構(gòu)信息獲取

更新時間：2021年01月04日 11:17:01 作者：_rtf

這篇文章主要介紹了pgsql 實(shí)現(xiàn)用戶自定義表結(jié)構(gòu)信息獲取，具有很好的參考價值，希望對大家有所幫助。一起跟隨小編過來看看吧

1. 獲取表中普通信息：如字段名，字段類型等

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

2.獲取所有的表和視圖

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

3.獲取約束注釋

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

4.獲取表的約束

-- conname 約束名稱
-- contype 約束類型(p:主鍵, f:外鍵, c: 檢查約束, u:唯一約束)
-- conkey 約束字段
-- confkey 外鍵字段
-- consrc 檢查約束條件
-- confreltable 外鍵字段引用的表
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'); -- 將 'TABLE-NAME' 換成自己的表

5.獲取表的觸發(fā)器

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

6.獲取字段的注釋

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

補(bǔ)充：查詢PostgreSQL庫中所有表的表結(jié)構(gòu)信息SQL

我就廢話不多說了，大家還是直接看代碼吧~

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 主鍵約束,
(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 唯一約束,
(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 外鍵約束,
(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;

以上為個人經(jīng)驗(yàn)，希望能給大家一個參考，也希望大家多多支持腳本之家。如有錯誤或未考慮完全的地方，望不吝賜教。

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