jiadong

SELECT LEVEL, LPAD('*', 2 * LEVEL - 1, '*') || JG_MC, SYS_CONNECT_BY_PATH(JG_MC||JG_id, '->') FROM xt_jgCONNECT BY PRIOR JG_ID = SJ_JGSTART WITH SJ_JG = '000000'ORDER BY LEVEL  ...

1. 将复杂的sql语句分解开。2. 学习窗口函数3. 编写高性能的sql语句4. 拓展至其他关系型数据库

10G在安装过程中选择了创建数据库，录入了用户名密码等安装成功后，数据库创建成功。此时通过pl/sql登录，选择normal登录提示如下图的错误而用sysdba可以正常登录 此时需要创建一个角色（）登录pl/sql --- by sysdab,输入以下代码执行create user jdd identified by jdd;grant dba to jdd;...

备忘： imp dj/dj@zcdb full=y file=d:\123.dmp

<url>jdbc:oracle:thin:@(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=ip1)(PORT=1521))(ADDRESS=(PROTOCOL=TCP)(HOST=ip2)(PORT=1521)))(FAILOVER=on)(LOAD_BALANCE=off)(CONNECT_DATA=(SERVER=...