﻿<?xml version="1.0" encoding="utf-8" standalone="yes"?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:trackback="http://madskills.com/public/xml/rss/module/trackback/" xmlns:wfw="http://wellformedweb.org/CommentAPI/" xmlns:slash="http://purl.org/rss/1.0/modules/slash/"><channel><title>BlogJava-飞翔的起点-随笔分类-oracle</title><link>http://www.blogjava.net/forgood/category/32177.html</link><description>从这里出发</description><language>zh-cn</language><lastBuildDate>Sat, 13 Dec 2008 16:44:14 GMT</lastBuildDate><pubDate>Sat, 13 Dec 2008 16:44:14 GMT</pubDate><ttl>60</ttl><item><title>oracle中sql优化</title><link>http://www.blogjava.net/forgood/archive/2008/12/13/246174.html</link><dc:creator>forgood</dc:creator><author>forgood</author><pubDate>Sat, 13 Dec 2008 15:14:00 GMT</pubDate><guid>http://www.blogjava.net/forgood/archive/2008/12/13/246174.html</guid><wfw:comment>http://www.blogjava.net/forgood/comments/246174.html</wfw:comment><comments>http://www.blogjava.net/forgood/archive/2008/12/13/246174.html#Feedback</comments><slash:comments>0</slash:comments><wfw:commentRss>http://www.blogjava.net/forgood/comments/commentRss/246174.html</wfw:commentRss><trackback:ping>http://www.blogjava.net/forgood/services/trackbacks/246174.html</trackback:ping><description><![CDATA[&nbsp;&nbsp;&nbsp;&nbsp; 摘要: 转自其他博客《收藏》（1）&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 选择最有效率的表名顺序(只在基于规则的优化器中有效)： ORACLE的解析器按照从右到左的顺序处理FROM子句中的表名，FROM子句中写在最后的表(基础表 driving table)将被最先处理，在FROM子句中包含多个表的情况下,你必须选择记录条数最少的表作为基础表。如果有3个以上的表连接查询,...&nbsp;&nbsp;<a href='http://www.blogjava.net/forgood/archive/2008/12/13/246174.html'>阅读全文</a><img src ="http://www.blogjava.net/forgood/aggbug/246174.html" width = "1" height = "1" /><br><br><div align=right><a style="text-decoration:none;" href="http://www.blogjava.net/forgood/" target="_blank">forgood</a> 2008-12-13 23:14 <a href="http://www.blogjava.net/forgood/archive/2008/12/13/246174.html#Feedback" target="_blank" style="text-decoration:none;">发表评论</a></div>]]></description></item><item><title>oracle中的锁表语句</title><link>http://www.blogjava.net/forgood/archive/2008/12/01/243668.html</link><dc:creator>forgood</dc:creator><author>forgood</author><pubDate>Mon, 01 Dec 2008 03:47:00 GMT</pubDate><guid>http://www.blogjava.net/forgood/archive/2008/12/01/243668.html</guid><wfw:comment>http://www.blogjava.net/forgood/comments/243668.html</wfw:comment><comments>http://www.blogjava.net/forgood/archive/2008/12/01/243668.html#Feedback</comments><slash:comments>0</slash:comments><wfw:commentRss>http://www.blogjava.net/forgood/comments/commentRss/243668.html</wfw:commentRss><trackback:ping>http://www.blogjava.net/forgood/services/trackbacks/243668.html</trackback:ping><description><![CDATA[//先锁表,然后再判断是否已经存在数据,以防止出现重复行<br />
<span style="color: red">&nbsp;&nbsp;&nbsp;String lockSql = "update YHZHMX set YHZHMX_DJBH=YHZHMX_DJBH where 1=2";</span><br />
//上面的语法貌似不好用.故采用下面的语法<br />
<span style="color: red">&nbsp;&nbsp;&nbsp;lockSql = "SELECT * FROM YHZHMX FOR UPDATE";</span>
<img src ="http://www.blogjava.net/forgood/aggbug/243668.html" width = "1" height = "1" /><br><br><div align=right><a style="text-decoration:none;" href="http://www.blogjava.net/forgood/" target="_blank">forgood</a> 2008-12-01 11:47 <a href="http://www.blogjava.net/forgood/archive/2008/12/01/243668.html#Feedback" target="_blank" style="text-decoration:none;">发表评论</a></div>]]></description></item></channel></rss>