定义常量:在sqlplus中之间输入define查看预定义的变量SYS@itkaifang> defineDEFINE _DATE = "07-MAR-17...
数据库在执行shutdownimmediate后用非SYS用户登录SQL*Plus报此错;[oracle@PROD ~]$ sqlplus scott/tigerSQL*Plus: Release 11.2.0.1.0 Product...
报错原因:在sqlplus中使用host命令然后exit返回,再此启动数据库会报此错;SYS@PROD> host[oracle@PROD ~]$ exitexit SYS@PROD> ![oracle@PROD ...
语法:INITCAP(列、字符串)SCOTT@itkaifang> SELECT INITCAP(ename) AS new,ename FROM emp;NEW &nbs...
语法:UPPER(列、字符串) LOWER(列、字符串)SCOTT@itkaifang> SELECT UPPER(ename),ename FROM&nbs...
语法:LENGTH(字符串) VSIZE(字符串)取字节数SCOTT@itkaifang> SELECT LENGTH(ename),empno FROM&n...
语法:REPLACE(被替换字符串,需替换的字符或变量,需显示的字符或变量)例:显示所有员工的姓名,用a替换所有"A"SCOTT@itkaifang> SELECT empno,ename FROM emp;  ...
语法:VSIZE(字符串)例:显示正好为5个字符的员工的姓名SCOTT@itkaifang> select empno,ename from emp where vsize(ename)=5; &...
语法:SUBSTR(被截取字符串,开始,结束)例:显示所有员工姓名的前5个字符;SCOTT@itkaifang> SELECT SUBSTR(ename,1,5) FROM emp;SUBSTR(ENAME,1,5)---------------...