Oracle笔记 三、function 、select

<div id="codeSnippetWrapper"> <div style="border-bottom-style: none; text-align: left; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; padding-left: 0px; width: 100%; padding-right: 0px; font-family: 'Courier New',courier,monospace; direction: ltr; border-top-style: none; color: black; font-size: 10pt; border-left-style: none; overflow: visible; padding-top: 0px" id="codeSnippet">
<pre style="border-bottom-style: none; text-align: left; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: 'Courier New',monospace; direction: ltr; border-top-style: none; color: black; font-size: 10pt; border-left-style: none; overflow: visible; padding-top: 0px">Scott表下有这么几个常用的表，而且还带有数据。分别是emp、dept、salgrade；

、>=、<=
 1500;
 1500  sal <= 5000  deptno = 10;
 2000;
 2000;
 s.losal  t.avg_sal < s.hisal;（）
 2;
 b.sal  rownum = 1;
 (