今天在测试12c的temp_undo的时候,准备在备库上测试一下,突然发现备库使用TNS连接竟然失败. 抛出的错误如下: $ sqlplus sys/oracle@testdb as sysdba SQL*Plus: Release 12.1.0.2.0 Production on Thu Dec 8 15:30:10 2016 Copyright (c) 1982, 2014, Oracle. All rights reserved. ERROR: ORA-12514: TNS:listene
1.首先建立远程连接 create public database link LINK_SJPSconnect to system identified by manager using '(DESCRIPTION =(ADDRESS_LIST =(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.20)(PORT = 1521)))(CONNECT_DATA =(SERVICE_NAME = GZZL)))'; 2.复制表结构 Create global
在ORACLE中,表连接方式主要有:内连接,外连接,自连接: 内连接: 这是最常用的连接查询 SELECT * FROM A INNER JOIN B ON A.ID=B.ID SELECT * FROM A JOIN B ON A.ID=B.ID SELECT *FROM A,B WHERE A.ID=B.ID 以上语句查询的结果一样的,都是内连接的使用场景. 外连接: LEFT JOIN,RIGHT JOIN,FULL JOIN 在外连接查询时,需要明白,基表和匹配表,基表即全是记录显示的表