Oracle表關聯(lián)更新幾種方法小結
更新時間:2024年05月24日 11:54:42 作者:zxrhhm
這篇文章主要介紹了Oracle表關聯(lián)更新幾種方法,本文通過實例代碼給大家介紹的非常詳細,具有一定的參考借鑒價值,對大家的學習或工作有一定的幫助,需要的朋友可以參考下
1、測試表及數據準備
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; -- 查詢表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 單列字段
-- update set 單列字段,更新滿足關聯(lián)條件的所有數據 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 單列字段 ,更新滿足特定條件ID=1的數據 update T_update01 T1 set infoname=(select T2.infoname from T_update02 T2 where T2.ID=T1.ID) where T1.ID=1; -- 本次執(zhí)行更新滿足特定條件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表多插入一行數據 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; -- 更新后檢查,sys_guid,infoname兩列的值和T_update02一樣了 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、使用游標
-- T_update02數據更新一下,方便使用游標更新的結果顯示 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 -- 使用用游標更新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; / -- 檢查查詢結果 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 -- 可以發(fā)現T_merg01表的ID=1的INFONAME=merge_into_Name1和T_merg02表ID=1的值一樣了 -- 可以發(fā)現T_merg01表多了一行數據是T_merg02表ID=3的這一行數據
5、Oracle 23c/AI 新特性
不論是已發(fā)版本Oracle23c free還是最終發(fā)布的長期支持的Oracle23Ai,表關聯(lián)更新update和刪除delete語句易用且更加優(yōu)雅,類似SQLServer的關聯(lián)更新
以下操作基于的環(huán)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、關聯(lián)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增強 表關聯(lián)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、關聯(lián)刪除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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