﻿<?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-谁动了我的代码-随笔分类-DataBase</title><link>http://www.blogjava.net/smcdl/category/38407.html</link><description>抽象即是空，空即是抽象。</description><language>zh-cn</language><lastBuildDate>Tue, 15 Dec 2009 17:06:52 GMT</lastBuildDate><pubDate>Tue, 15 Dec 2009 17:06:52 GMT</pubDate><ttl>60</ttl><item><title>如何设置MySQL的Timestamp为默认NULL？</title><link>http://www.blogjava.net/smcdl/archive/2009/12/09/305338.html</link><dc:creator>teddy</dc:creator><author>teddy</author><pubDate>Wed, 09 Dec 2009 13:49:00 GMT</pubDate><guid>http://www.blogjava.net/smcdl/archive/2009/12/09/305338.html</guid><wfw:comment>http://www.blogjava.net/smcdl/comments/305338.html</wfw:comment><comments>http://www.blogjava.net/smcdl/archive/2009/12/09/305338.html#Feedback</comments><slash:comments>0</slash:comments><wfw:commentRss>http://www.blogjava.net/smcdl/comments/commentRss/305338.html</wfw:commentRss><trackback:ping>http://www.blogjava.net/smcdl/services/trackbacks/305338.html</trackback:ping><description><![CDATA[在MYSQL中如果在建表的时候没有指定Timestamp字段是否为NULL，则系统自动添加默认值，使用DEFAULT NULL也不好用，其实是可以使用NULL直接指定的，如下：<br />
<br />
`CREATE_DATE` TIMESTAMP NULL<br />
<br />
<br />
<br />
<img src ="http://www.blogjava.net/smcdl/aggbug/305338.html" width = "1" height = "1" /><br><br><div align=right><a style="text-decoration:none;" href="http://www.blogjava.net/smcdl/" target="_blank">teddy</a> 2009-12-09 21:49 <a href="http://www.blogjava.net/smcdl/archive/2009/12/09/305338.html#Feedback" target="_blank" style="text-decoration:none;">发表评论</a></div>]]></description></item><item><title>Oracle Distinct注意事项</title><link>http://www.blogjava.net/smcdl/archive/2009/03/19/260895.html</link><dc:creator>teddy</dc:creator><author>teddy</author><pubDate>Thu, 19 Mar 2009 12:49:00 GMT</pubDate><guid>http://www.blogjava.net/smcdl/archive/2009/03/19/260895.html</guid><wfw:comment>http://www.blogjava.net/smcdl/comments/260895.html</wfw:comment><comments>http://www.blogjava.net/smcdl/archive/2009/03/19/260895.html#Feedback</comments><slash:comments>0</slash:comments><wfw:commentRss>http://www.blogjava.net/smcdl/comments/commentRss/260895.html</wfw:commentRss><trackback:ping>http://www.blogjava.net/smcdl/services/trackbacks/260895.html</trackback:ping><description><![CDATA[在使用Distinct时，不能直接对count操作，需要通过子查询来实现，如下<br />
select count(1) from (select distinct * from table_name)<br />
<br />
<img src ="http://www.blogjava.net/smcdl/aggbug/260895.html" width = "1" height = "1" /><br><br><div align=right><a style="text-decoration:none;" href="http://www.blogjava.net/smcdl/" target="_blank">teddy</a> 2009-03-19 20:49 <a href="http://www.blogjava.net/smcdl/archive/2009/03/19/260895.html#Feedback" target="_blank" style="text-decoration:none;">发表评论</a></div>]]></description></item><item><title>Oracle数据库建立Synonym</title><link>http://www.blogjava.net/smcdl/archive/2009/03/19/260894.html</link><dc:creator>teddy</dc:creator><author>teddy</author><pubDate>Thu, 19 Mar 2009 12:48:00 GMT</pubDate><guid>http://www.blogjava.net/smcdl/archive/2009/03/19/260894.html</guid><wfw:comment>http://www.blogjava.net/smcdl/comments/260894.html</wfw:comment><comments>http://www.blogjava.net/smcdl/archive/2009/03/19/260894.html#Feedback</comments><slash:comments>0</slash:comments><wfw:commentRss>http://www.blogjava.net/smcdl/comments/commentRss/260894.html</wfw:commentRss><trackback:ping>http://www.blogjava.net/smcdl/services/trackbacks/260894.html</trackback:ping><description><![CDATA[<font face="Verdana" size="2">通过dblink查询表&nbsp; </font><font face="Verdana" size="2">select * from <a href="&#109;&#97;&#105;&#108;&#116;&#111;&#58;&#97;&#112;&#112;&#115;&#46;&#99;&#117;&#120;&#95;&#112;&#114;&#109;&#95;&#115;&#112;&#95;&#118;&#101;&#110;&#100;&#111;&#114;&#95;&#118;&#64;&#112;&#114;&#109;&#101;&#114;&#112;">schema_name.table_or_view_name@dblink</a></font><br />
<font face="Verdana" size="2">建立Synonym &nbsp;&nbsp;&nbsp; create synonym synonym_name for schema_name<a href="&#109;&#97;&#105;&#108;&#116;&#111;&#58;&#97;&#112;&#112;&#115;&#46;&#99;&#117;&#120;&#95;&#112;&#114;&#109;&#95;&#100;&#101;&#112;&#97;&#114;&#116;&#109;&#101;&#110;&#116;&#95;&#118;&#64;&#112;&#114;&#109;&#101;&#114;&#112;">.table_or_view_name@dblink</a><br />
<br />
</font>
<img src ="http://www.blogjava.net/smcdl/aggbug/260894.html" width = "1" height = "1" /><br><br><div align=right><a style="text-decoration:none;" href="http://www.blogjava.net/smcdl/" target="_blank">teddy</a> 2009-03-19 20:48 <a href="http://www.blogjava.net/smcdl/archive/2009/03/19/260894.html#Feedback" target="_blank" style="text-decoration:none;">发表评论</a></div>]]></description></item></channel></rss>