﻿<?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-fish的Blog-文章分类-oracle</title><link>http://www.blogjava.net/yjj317/category/16021.html</link><description>在浮躁的年代里，我们进取心太切，患得患失；虚荣心太强，战战兢兢。一心争强好胜，惟恐榜上无名。</description><language>zh-cn</language><lastBuildDate>Fri, 02 Mar 2007 06:46:19 GMT</lastBuildDate><pubDate>Fri, 02 Mar 2007 06:46:19 GMT</pubDate><ttl>60</ttl><item><title>oracle的nvl函数的用法</title><link>http://www.blogjava.net/yjj317/articles/73833.html</link><dc:creator>fish的Blog</dc:creator><author>fish的Blog</author><pubDate>Sun, 08 Oct 2006 07:19:00 GMT</pubDate><guid>http://www.blogjava.net/yjj317/articles/73833.html</guid><wfw:comment>http://www.blogjava.net/yjj317/comments/73833.html</wfw:comment><comments>http://www.blogjava.net/yjj317/articles/73833.html#Feedback</comments><slash:comments>0</slash:comments><wfw:commentRss>http://www.blogjava.net/yjj317/comments/commentRss/73833.html</wfw:commentRss><trackback:ping>http://www.blogjava.net/yjj317/services/trackbacks/73833.html</trackback:ping><description><![CDATA[      通过查询获得某个字段的合计值，如果这个值位null将给出一个预设的默认值<br /><font color="#000000">select nvl(sum(t.dwxhl),1) from tb_jhde t where zydm=-1</font>这里关心的nvl的用法，nvl（arg,value）代表如果前面的arg的值为null那么返回的值为后面的value<br /><br />如: <font face="verdana, arial, helvetica" size="2"><span class="javascript" id="text998253">NVL(a,b)就是判断a是否是NULL,如果不是返回a的值，如果是返回b的值</span></font><br /><img src ="http://www.blogjava.net/yjj317/aggbug/73833.html" width = "1" height = "1" /><br><br><div align=right><a style="text-decoration:none;" href="http://www.blogjava.net/yjj317/" target="_blank">fish的Blog</a> 2006-10-08 15:19 <a href="http://www.blogjava.net/yjj317/articles/73833.html#Feedback" target="_blank" style="text-decoration:none;">发表评论</a></div>]]></description></item></channel></rss>