<?xml version="1.0" encoding="utf-8" ?><rss version="2.0"><channel><title><![CDATA[tengteng721的专栏]]></title><description><![CDATA[]]></description><link>https://blog.youkuaiyun.com/tengteng721</link><language>zh-cn</language><generator>https://blog.youkuaiyun.com/</generator><copyright><![CDATA[Copyright &copy; tengteng721]]></copyright><item><title><![CDATA[sql row_number() over(...)]]></title><link>https://blog.youkuaiyun.com/tengteng721/article/details/84160740</link><guid>https://blog.youkuaiyun.com/tengteng721/article/details/84160740</guid><author>tengteng721</author><pubDate>Wed, 29 Feb 2012 14:20:18 +0800</pubDate><description><![CDATA[将各部门的员工按薪水排序 select ename,job,deptno,sal,(row_number() over(partition by deptno order by sal desc)) as 排名 --先按部门分组，再在部门中按薪水降序排名 from scott.emp
 
 ...]]></description><category></category></item><item><title><![CDATA[sql  替换 空格]]></title><link>https://blog.youkuaiyun.com/tengteng721/article/details/84084065</link><guid>https://blog.youkuaiyun.com/tengteng721/article/details/84084065</guid><author>tengteng721</author><pubDate>Thu, 17 Nov 2011 11:10:22 +0800</pubDate><description><![CDATA[sql  
1. 去掉 左右 空格
ltrim()去除左空格rtrim()去除右空格。
select ltrim(rtrim(UsrName))

2. 将多个空格换成一个空格
update 表 s set b(需替换的字段) = REGEXP_REPLACE(b ,'( ){2,}', ' ');

java

多个空格换成一个空格
.replaceAll(&quot; {2,}&quot;,...]]></description><category></category></item><item><title><![CDATA[Jprofile  性能优化]]></title><link>https://blog.youkuaiyun.com/tengteng721/article/details/84005469</link><guid>https://blog.youkuaiyun.com/tengteng721/article/details/84005469</guid><author>tengteng721</author><pubDate>Mon, 22 Aug 2011 12:41:53 +0800</pubDate><description><![CDATA[由于要对系统进行性能优化，这两天用了下Jprofile,发现还是很强大滴。 
服务器 :Linux     Websphere 

配置过程见附件]]></description><category></category></item><item><title><![CDATA[查 是谁 锁 的 什么 表]]></title><link>https://blog.youkuaiyun.com/tengteng721/article/details/83835530</link><guid>https://blog.youkuaiyun.com/tengteng721/article/details/83835530</guid><author>tengteng721</author><pubDate>Thu, 27 Jan 2011 19:25:14 +0800</pubDate><description><![CDATA[1.查被锁的表明和sid
select a.sid,p.spid,c.object_name,b.oracle_username,b.session_id
from v$process p,v$session a,v$locked_object b,all_objects c
where p.addr=a.paddr and a.process=b.process and c.object_...]]></description><category></category></item><item><title><![CDATA[java  运算符 优先级]]></title><link>https://blog.youkuaiyun.com/tengteng721/article/details/83776851</link><guid>https://blog.youkuaiyun.com/tengteng721/article/details/83776851</guid><author>tengteng721</author><pubDate>Thu, 09 Dec 2010 13:44:18 +0800</pubDate><description><![CDATA[运算符优先级表
优先级 运算符 结合性 
1  () [] .                  从左到右 
2  ! +(正)  -(负) ~ ++ --    从右向左 
3   * / %                   从左向右 
4  +(加) -(减)               从左向右 
5      &gt; &gt;&gt;&gt;               从左向右 
6    ...]]></description><category></category></item><item><title><![CDATA[环境变量path  改变了，但 java -version后显示jdk版本不变的解决方法]]></title><link>https://blog.youkuaiyun.com/tengteng721/article/details/83772445</link><guid>https://blog.youkuaiyun.com/tengteng721/article/details/83772445</guid><author>tengteng721</author><pubDate>Wed, 01 Dec 2010 14:39:20 +0800</pubDate><description><![CDATA[今天遇到了一个问题，我将环境变量的path设置成新的jdk时，用java -version后，发现显示jdk版本号没有变化，最后将%JAVA_HOME%\bin;放到的Path的最前面，问题就解决了...]]></description><category></category></item><item><title><![CDATA[oracle 文件init.ora , listener.ora, tnsname.ora 中部分变量说明]]></title><link>https://blog.youkuaiyun.com/tengteng721/article/details/83771822</link><guid>https://blog.youkuaiyun.com/tengteng721/article/details/83771822</guid><author>tengteng721</author><pubDate>Tue, 30 Nov 2010 15:48:33 +0800</pubDate><description><![CDATA[[color=red]init.ora[/color]
1.db_name 是数据库的名称，在db安装时就已经设置了，不可修改
2.instance_name 是实例名，是数据库运行中名称
3.service_name 应为数据库网络连接时的名称。这个值可随意改动，并且还可以有多个值

[color=red]listener.ora[/color]
1.SID_NAME,SID_NAM...]]></description><category></category></item><item><title><![CDATA[jdbc  得到表的所有列名和类型]]></title><link>https://blog.youkuaiyun.com/tengteng721/article/details/83771799</link><guid>https://blog.youkuaiyun.com/tengteng721/article/details/83771799</guid><author>tengteng721</author><pubDate>Tue, 30 Nov 2010 15:15:38 +0800</pubDate><description><![CDATA[public String getAllFields(String tablename){
Connection conn=null;
Statement st=null;
ResultSet rs=null;
ResultSetMetaData rsm=null;

String userName=&quot;****&quot;;
String passwd=&quot;&quot;****&quot;;		
String u...]]></description><category></category></item><item><title><![CDATA[oracle  索引]]></title><link>https://blog.youkuaiyun.com/tengteng721/article/details/83771791</link><guid>https://blog.youkuaiyun.com/tengteng721/article/details/83771791</guid><author>tengteng721</author><pubDate>Tue, 30 Nov 2010 14:59:19 +0800</pubDate><description><![CDATA[建立索引
1. create index mycolumn_index on mytable(myclumn)  (此为非聚集索引)

建立聚簇索引（可以使用关键字CLUSTERED）一个表只能有一个聚簇索引
2.create CLUSTERED INDEX mycolumn_clust_index ON mytable(mycolumn)

删除索引
3.drop INDEX my...]]></description><category></category></item><item><title><![CDATA[oracle  查用户所有表，所有函数和存储过程，所有用户，当前用户连接，用户权限,service name...]]></title><link>https://blog.youkuaiyun.com/tengteng721/article/details/83771783</link><guid>https://blog.youkuaiyun.com/tengteng721/article/details/83771783</guid><author>tengteng721</author><pubDate>Tue, 30 Nov 2010 14:45:17 +0800</pubDate><description><![CDATA[1.oracle查用户表空间
select * from user_all_tables

2.oracle查询所有函数和存储过程
select * from user_source

3.oracle查询所有用户
select * from all_users
select * from dba_users

4.oracle查看当前用户连接
select * from V...]]></description><category></category></item><item><title><![CDATA[取sql 结果的的  前 n 列]]></title><link>https://blog.youkuaiyun.com/tengteng721/article/details/83771632</link><guid>https://blog.youkuaiyun.com/tengteng721/article/details/83771632</guid><author>tengteng721</author><pubDate>Tue, 30 Nov 2010 11:09:36 +0800</pubDate><description><![CDATA[SqlServer:
select top n COLUMNNAME from TABLENAME;
eg: select top 2 * from customer;

ORACLE:
select COLUMNNAME from TABLENAME where ROWNUM]]></description><category></category></item><item><title><![CDATA[table  隐藏一列]]></title><link>https://blog.youkuaiyun.com/tengteng721/article/details/83771626</link><guid>https://blog.youkuaiyun.com/tengteng721/article/details/83771626</guid><author>tengteng721</author><pubDate>Tue, 30 Nov 2010 11:02:22 +0800</pubDate><description><![CDATA[

 一
 1


 二
 2

]]></description><category></category></item><item><title><![CDATA[js  表格拖拽]]></title><link>https://blog.youkuaiyun.com/tengteng721/article/details/83769787</link><guid>https://blog.youkuaiyun.com/tengteng721/article/details/83769787</guid><author>tengteng721</author><pubDate>Fri, 26 Nov 2010 12:26:54 +0800</pubDate><description><![CDATA[前几天看到网上一个table拖拽的例子，自己改了改，改成自己需要的了



拖动

td{width:20%;height:20px;cursor:default;}
div{font-size:13px;}..
table{border:1px solid black;font-size:13px;}


	var dragedTable_x0,dragedTable_y0...]]></description><category></category></item><item><title><![CDATA[数据库 范式]]></title><link>https://blog.youkuaiyun.com/tengteng721/article/details/83645147</link><guid>https://blog.youkuaiyun.com/tengteng721/article/details/83645147</guid><author>tengteng721</author><pubDate>Sat, 19 Jun 2010 23:32:18 +0800</pubDate><description><![CDATA[1 第一范式（1NF）无重复的列 
      所谓第一范式（1NF）是指数据库表的每一列都是不可分割的基本数据项，同一列中不能有多个值，即实体中的某个属性不能有多个值或者不能有重复的属性。如果出现重复的属性，就可能需要定义一个新的实体，新的实体由重复的属性构成，新实体与原实体之间为一对多关系。在第一范式（1NF）中表的每一行只包含一个实例的信息。简而言之，第一范式就是无重复的列。 

说明...]]></description><category></category></item></channel></rss>