document.write("<div class=\"item\">    <div class=\"title\"><a href=\"http://www.itpow.com/c/2007/04/I9VYNLQVMZ60X1CT.asp\" target=\"_blank\"><span class=\"key\">设置</span> <span class=\"key\">UNIQUE</span> <span class=\"key\">约束</span><span class=\"key\">技术</span><span class=\"key\">一则</span></a></div>    <div class=\"abstract\"><span class=\"pubDate\">2007年04月11日</span> 设立 <span class=\"key\">UNIQUE</span> <span class=\"key\">约束</span>。表一，区县表：一、只为区县代码<span class=\"key\">设置</span><span class=\"key\">约束</span>。二、只为区县名称<span class=\"key\">设置</span><span class=\"key\">约束</span>。三、为区县代码和区县名称<span class=\"key\">设置</span>联合<span class=\"key\">约束</span>。四、为区县代码和区县名称分别<span class=\"key\">设置</span><span class=\"key\">约束</span>。</div>    <div class=\"url\"><a href=\"http://www.itpow.com/c/2007/04/I9VYNLQVMZ60X1CT.asp\" target=\"_blank\">http://www.itpow.com/c/2007/04/I9VYNLQVMZ60X1CT.asp</a></div></div><div class=\"item\">    <div class=\"title\"><a href=\"http://www.itpow.com/c/2008/09/T1FFO9P644PMH0DZ.asp\" target=\"_blank\">键与<span class=\"key\">约束</span></a></div>    <div class=\"abstract\"><span class=\"pubDate\">2008年09月16日</span> 与聚集索引键与<span class=\"key\">约束</span>如何创建键与主键如何创建聚集索引与非聚集索引再谈键、索引、唯一性、聚集的关系实际上键也是一种<span class=\"key\">约束</span>，我们可以建立一个主键，然后建立一个<span class=\"key\">约束</span>，导出 SQL 语</div>    <div class=\"url\"><a href=\"http://www.itpow.com/c/2008/09/T1FFO9P644PMH0DZ.asp\" target=\"_blank\">http://www.itpow.com/c/2008/09/T1FFO9P644PMH0DZ.asp</a></div></div>")