Oracle表关联更新几种方法小结
作者:zxrhhm
这篇文章主要介绍了Oracle表关联更新几种方法,本文通过实例代码给大家介绍的非常详细,具有一定的参考借鉴价值,对大家的学习或工作有一定的帮助,需要的朋友可以参考下
1、测试表及数据准备
create table T_update01(ID int ,infoname varchar2(32),sys_guid varchar2(36)); create table T_update02(ID int ,infoname varchar2(32),sys_guid varchar2(36)); insert into T_update01 select 1,N'1_updateName',sys_guid() from dual union select 2,N'2_updateName',sys_guid() from dual; commit; insert into T_update02 select 1,N'update_set_exists',sys_guid() from dual; insert into T_update02 select 2,N'update_set_cursor',sys_guid() from dual; insert into T_update02 select 3,N'3_Name',sys_guid() from dual; commit; -- 查询表T_update01、T_update02 select * from T_update01; ID INFONAME SYS_GUID ---------- ------------------------------ ------------------------------------ 1 1_updateName 189F5A1099BF6606E0639C0AA8C0F15E 2 2_updateName 189F5A1099C06606E0639C0AA8C0F15E select * from T_update02; ID INFONAME SYS_GUID ---------- ------------------------------ ------------------------------------ 1 update_set_exists 189F5A1099C46606E0639C0AA8C0F15E 2 update_set_cursor 189F5A1099C56606E0639C0AA8C0F15E 3 3_Name 189F5A1099C66606E0639C0AA8C0F15E
2、update set column ... where exists
2.1、update set 单列字段
-- update set 单列字段,更新满足关联条件的所有数据 update T_update01 T1 set infoname=(select T2.infoname from T_update02 T2 where T2.ID=T1.ID) where exists (select 1 from T_update02 T2 where T2.ID=T1.ID ); -- update set 单列字段 ,更新满足特定条件ID=1的数据 update T_update01 T1 set infoname=(select T2.infoname from T_update02 T2 where T2.ID=T1.ID) where T1.ID=1; -- 本次执行更新满足特定条件T_update01表的ID=1 SCOTT@prod02> select * from T_update01; ID INFONAME SYS_GUID ---------- ------------------------------ ------------------------------------ 1 update_set_exists 189F5A1099BF6606E0639C0AA8C0F15E 2 2_updateName 189F5A1099C06606E0639C0AA8C0F15E
2.2、update set 多列字段
-- T_update01表多插入一行数据 insert into T_update01 select 3,N'insert03',sys_guid() from dual; commit; select * from T_update01; ID INFONAME SYS_GUID ---------- ------------------------------ ------------------------------------ 1 update_set_exists 189F5A1099BF6606E0639C0AA8C0F15E 2 2_updateName 189F5A1099C06606E0639C0AA8C0F15E 3 insert03 189F5A1099C76606E0639C0AA8C0F15E update T_update01 T1 set (sys_guid,infoname) = (select T2.sys_guid,T2.infoname from T_update02 T2 where T2.ID=T1.ID) where exists (select 1 from T_update02 T2 where T2.ID=T1.ID ); commit; -- 更新后检查,sys_guid,infoname两列的值和T_update02一样了 select * from T_update01; ID INFONAME SYS_GUID ---------- ------------------------------ ------------------------------------ 1 update_set_exists 189F5A1099C46606E0639C0AA8C0F15E 2 update_set_cursor 189F5A1099C56606E0639C0AA8C0F15E 3 3_Name 189F5A1099C66606E0639C0AA8C0F15E select * from T_update02; ID INFONAME SYS_GUID ---------- ------------------------------ ------------------------------------ 1 update_set_exists 189F5A1099C46606E0639C0AA8C0F15E 2 update_set_cursor 189F5A1099C56606E0639C0AA8C0F15E 3 3_Name 189F5A1099C66606E0639C0AA8C0F15E
3、使用游标
-- T_update02数据更新一下,方便使用游标更新的结果显示 update T_update02 set INFONAME='cursor is select' where id>=2; commit; select * from T_update02; ID INFONAME SYS_GUID ---------- ------------------------------ ------------------------------------ 1 update_set_exists 189F5A1099C46606E0639C0AA8C0F15E 2 cursor is select 189F5A1099C56606E0639C0AA8C0F15E 3 cursor is select 189F5A1099C66606E0639C0AA8C0F15E -- 使用用游标更新T_update01的INFONAME字段,使其和T_update02 where id>=2 declare cursor cur_my_source is select infoname,id from T_update02; begin for cur_my_target in cur_my_source loop update T_update01 set infoname=cur_my_target.infoname where id=cur_my_target.id; end loop; commit; end; / -- 检查查询结果 select * from T_update01; ID INFONAME SYS_GUID ---------- ------------------------------ ------------------------------------ 1 update_set_exists 189F5A1099C46606E0639C0AA8C0F15E 2 cursor is select 189F5A1099C56606E0639C0AA8C0F15E 3 cursor is select 189F5A1099C66606E0639C0AA8C0F15E
4、merge into子句
create table T_merg01(ID int ,infoname varchar2(32),sys_guid varchar2(36)); create table T_merg02(ID int ,infoname varchar2(32),sys_guid varchar2(36)); insert into T_merg01 select 1,N'1_Name',sys_guid() from dual union select 2,N'2_Name',sys_guid() from dual; commit; select * from T_merg01; ID INFONAME SYS_GUID ---------- ------------------------------ ------------------------------------ 1 1_Name 189F5A1099BB6606E0639C0AA8C0F15E 2 2_Name 189F5A1099BC6606E0639C0AA8C0F15E insert into T_merg02 select 1,N'merge_into_Name1',sys_guid() from dual; insert into T_merg02 select 3,N'3_Name',sys_guid() from dual; select * from T_merg02; ID INFONAME SYS_GUID ---------- ------------------------------ ------------------------------------ 1 merge_into_Name1 189F5A1099BD6606E0639C0AA8C0F15E 3 3_Name 189F5A1099BE6606E0639C0AA8C0F15E merge into T_merg01 T1 using T_merg02 T2 on (T1.id=T2.id) when matched then update set infoname=T2.infoname when not matched then insert (ID,infoname,sys_guid) values(T2.ID ,T2.infoname,T2.sys_guid); commit; select * from T_merg01; ID INFONAME SYS_GUID ---------- ------------------------------ ------------------------------------ 1 merge_into_Name1 189F5A1099BB6606E0639C0AA8C0F15E 2 2_Name 189F5A1099BC6606E0639C0AA8C0F15E 3 3_Name 189F5A1099BE6606E0639C0AA8C0F15E -- 可以发现T_merg01表的ID=1的INFONAME=merge_into_Name1和T_merg02表ID=1的值一样了 -- 可以发现T_merg01表多了一行数据是T_merg02表ID=3的这一行数据
5、Oracle 23c/AI 新特性
不论是已发版本Oracle23c free还是最终发布的长期支持的Oracle23Ai,表关联更新update和删除delete语句易用且更加优雅,类似SQLServer的关联更新
以下操作基于的环境
SQL*Plus: Release 23.0.0.0.0 - Developer-Release on Fri May 17 11:17:54 2024
Version 23.2.0.0.0
5.1、关联更新update
TESTUSER@FREEPDB1> create table t_emp as select EMPLOYEE_ID,DEPARTMENT_ID,SALARY from employees; Table created. TESTUSER@FREEPDB1> desc t_emp; Name Null? Type ----------------------------------------- -------- ---------------------------- EMPLOYEE_ID NUMBER(6) DEPARTMENT_ID NUMBER(4) SALARY NUMBER(8,2) TESTUSER@FREEPDB1> select * from t_emp where DEPARTMENT_ID=110; EMPLOYEE_ID DEPARTMENT_ID SALARY ----------- ------------- ---------- 205 110 12008 206 110 8300 TESTUSER@FREEPDB1> update t_emp set DEPARTMENT_ID=null,SALARY=null where DEPARTMENT_ID=110; 2 rows updated. TESTUSER@FREEPDB1> commit; Commit complete. TESTUSER@FREEPDB1> select * from t_emp where DEPARTMENT_ID is null; EMPLOYEE_ID DEPARTMENT_ID SALARY ----------- ------------- ---------- 178 7000 205 206 -- oracle 23c SQL增强 表关联更新 TESTUSER@FREEPDB1> update t_emp t1 set t1.DEPARTMENT_ID=t2.DEPARTMENT_ID,t1.SALARY=t2.SALARY from employees t2 where t2.EMPLOYEE_ID=t1.EMPLOYEE_ID and t1.DEPARTMENT_ID is null; 3 row updated. TESTUSER@FREEPDB1> commit; Commit complete. TESTUSER@FREEPDB1> select t1.* from t_emp t1 where t1.DEPARTMENT_ID=110; EMPLOYEE_ID DEPARTMENT_ID SALARY ----------- ------------- ---------- 205 110 12008 206 110 8300
5.2、关联删除delete
TESTUSER@FREEPDB1> delete t_emp t1 from employees t2 where t2.EMPLOYEE_ID=t1.EMPLOYEE_ID and t2.DEPARTMENT_ID=110; 45 rows deleted. TESTUSER@FREEPDB1> commit; Commit complete. TESTUSER@FREEPDB1> select t1.* from t_emp t1 where t1.DEPARTMENT_ID=110; no rows selected
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