易截截图软件、单文件、免安装、纯绿色、仅160KB

oracle 的两个替换函数 REPLACE TRANSLATE


replace就是一般意义上的字符串替换,translate只是一个字符替换对应的一个字符,下面有手册说明,还有例子 O(∩_∩)O哈哈~
REPLACE
Syntax
Purpose
REPLACE returns char with every occurrence of search_string replaced with replacement_string. If replacement_string is omitted or null, then all occurrences of search_string are removed. If search_string is null, then char is returned.
Both search_string and replacement_string, as well as char, can be any of the datatypes CHAR, VARCHAR2, NCHAR, NVARCHAR2, CLOB, or NCLOB. The string returned is in the same character set as char. The function returns VARCHAR2 if the first argument is not a LOB and returns CLOB if the first argument is a LOB.
REPLACE provides functionality related to that provided by the TRANSLATE function. TRANSLATE provides single-character, one-to-one substitution. REPLACE lets you substitute one string for another as well as to remove character strings.
Examples
The following example replaces occurrences of J with BL:
SELECT REPLACE('JACK and JUE','J','BL') "Changes"
from DUAL;
Changes
--------------
BLACK and BLUE
TRANSLATE
Syntax
PurposeTRANSLATE returns expr with all occurrences of each character in from_string replaced by its corresponding character in to_string.
Characters in expr that are not in from_string are not replaced. If expr is a character string, then you must enclose it in single
quotation marks. The argument from_string can contain more characters than to_string. In this case, the extra characters at the
end of from_string have no corresponding characters in to_string. If these extra characters appear in char, then they are removed
from the return value.
You cannot use an empty string for to_string to remove all characters in from_string from the return value. Oracle Database
interprets the empty string as null, and if this function has a null argument, then it returns null.
TRANSLATE provides functionality related to that provided by the REPLACE function


相关文档:

Oracle 字段类型

Oracle 字段类型
字段类型
描述
字段长度及其缺省值
CHAR (size ) 
用于保存定长(size)字节的字符串数据。
每行定长(不足部分补为空格);最大长度为每行2000字节,缺省值为每行1字节。设置长度(size)前需考虑字符集为单字节或多字节。
VARCHAR2 (size ) 
用于保存变长的字符串数据。其中最大字节长 ......

Oracle常用命令

1. 修改redo log file大小
SQL> select group#,status from v$log;
SQL> alter database add logfile group 4 'F:\oracle\product\10.2.0\oradata\orcl\REDO04.LOG' size 512m;
SQL> alter system switch logfile;
SQL> select group#,status from v$log;
2. 修改large_pool_size大小
SQL> alter  ......

oracle 列转行实例

select * from (select pro_id, sum(decode(month, '01', summ)) one,
                    sum(decode(month, '02', summ)) two,
             &nb ......

Oracle 目录服务

Create directory让我们可以在Oracle数据库中灵活的对文件进行读写操作,极大的提高了Oracle的易用性和可扩展性。
其语法为:
CREATE [OR REPLACE] DIRECTORY directory
AS 'pathname
';
本案例具体创建如下:
create or replace directory exp_dir as '/tmp';
目录创建以后,就可以把读写权限授予特定用 ......

Sybase数据库和oracle数据库用法


1 将数据库TEST完全导出,用户名system 密码manager 导出到D:daochu.dmp中
    exp system/manager@TEST file=d:daochu.dmp full=y
2 将数据库中system用户与sys用户的表导出
    exp system/manager@TEST file=d:daochu.dmp owner=(system,sys)
3 将数据库中的表inner_notify、notify_ ......
© 2009 ej38.com All Rights Reserved. 关于E健网联系我们 | 站点地图 | 赣ICP备09004571号