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分享SQL查询去掉重复的列,我这见鬼了，不知道错误在哪里？
我想查询某个表其中的一个字段的值，同时去掉它重复的元素，请问查询语句应该怎么写啊？
我是这样写的：
String condition = "SELECT DISTINCT Type FROM tb_Bookinfo ";
ResultSet rs_type = dbO.executeQuery(condition)
我就想去掉Type中重复的值，请高手指点啊。
我是这样写的：
String condition = "SELECT DISTINCT Type FROM tb_Bookinfo ";
ResultSet rs_type = dbO.executeQuery(condition)
我就想去掉Type中重复的值，请高手指点啊。
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wuxuan13 2011-05-12
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你这个也搞的太复杂了吧
靠
靠
scomouse 2008-07-01
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根据sql语句 SELECT DISTINCT Type FROM tb_Bookinfo ，您选择了一列，数据库将返回一列。
根据 rs_type.getString(3)您要求获取第三列，唉！
根据 rs_type.getString(3)您要求获取第三列，唉！
ilrxx 2007-05-07
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<%
String condition = "SELECT DISTINCT Type FROM tb_Bookinfo ";
ResultSet rs_type = dbO.executeQuery(condition);
%>
<body>
<div id="Layer1"><jsp:include page="Tail.jsp"/></div>
<div id="Layer2">
<table width="188" height="84">
<tr>
<td height="36" colspan="2" background="Images/bg_booksort.gif">
<table width="174">
<tr>
<td width="42"><div align="right"><img src="Images/ico_booksort.gif" width="25" height="25" /></div></td>
<td width="120">图书分类列表</td>
</tr>
</table></td>
</tr>
<%while(rs_type.next()){%>
<tr>
<td width="32" height="40"> <img src="Images/boardlist.gif" width="25" height="14" /></td>
<td width="144"><%=rs_type.getString(3)%></td>
</tr>
<%}%>
</table>
主要是这段
String condition = "SELECT DISTINCT Type FROM tb_Bookinfo ";
ResultSet rs_type = dbO.executeQuery(condition);
%>
<body>
<div id="Layer1"><jsp:include page="Tail.jsp"/></div>
<div id="Layer2">
<table width="188" height="84">
<tr>
<td height="36" colspan="2" background="Images/bg_booksort.gif">
<table width="174">
<tr>
<td width="42"><div align="right"><img src="Images/ico_booksort.gif" width="25" height="25" /></div></td>
<td width="120">图书分类列表</td>
</tr>
</table></td>
</tr>
<%while(rs_type.next()){%>
<tr>
<td width="32" height="40"> <img src="Images/boardlist.gif" width="25" height="14" /></td>
<td width="144"><%=rs_type.getString(3)%></td>
</tr>
<%}%>
</table>
主要是这段
ilrxx 2007-05-07
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<%@ page contentType="text/html; charset=gb2312" language="java" import="java.sql.*" errorPage="" %>
<jsp:useBean id="dbO" scope="page" class="beans.DBoperation"/>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<link rel="stylesheet" href="CSS/style.css" type="text/css" media="screen">
<style type="text/css">
<!--
#Layer1 {
position:absolute;
left:102px;
top:1132px;
width:972px;
height:40px;
z-index:1;
}
#Layer2 {
position:absolute;
left:350px;
top:633px;
width:186px;
height:477px;
z-index:2;
}
#Layer3 {
position:absolute;
left:580px;
top:640px;
width:519px;
height:27px;
z-index:3;
}
#Layer4 {
position:absolute;
left:556px;
top:685px;
width:512px;
height:38px;
z-index:4;
}
#Layer5 {
position:absolute;
left:559px;
top:735px;
width:508px;
height:51px;
z-index:5;
}
-->
</style>
</head>
<%
String condition = "SELECT DISTINCT Type FROM tb_Bookinfo ";
ResultSet rs_type = dbO.executeQuery(condition);
%>
<body>
<div id="Layer1"><jsp:include page="Tail.jsp"/></div>
<div id="Layer2">
<table width="188" height="84">
<tr>
<td height="36" colspan="2" background="Images/bg_booksort.gif">
<table width="174">
<tr>
<td width="42"><div align="right"><img src="Images/ico_booksort.gif" width="25" height="25" /></div></td>
<td width="120">图书分类列表</td>
</tr>
</table></td>
</tr>
<%while(rs_type.next()){%>
<tr>
<td width="32" height="40"> <img src="Images/boardlist.gif" width="25" height="14" /></td>
<td width="144"><%=rs_type.getString(3)%></td>
</tr>
<%}%>
</table>
</div>
<div id="Layer3">
<table width="514" height="25">
<tr>
<td><div align="left">图书类别: [ ] </div></td>
</tr>
</table>
</div>
<div id="Layer4">
<table width="511" height="39">
<tr>
<td width="18"> </td>
<td width="182">书名</td>
<td width="205">出版社</td>
<td width="86">购买</td>
</tr>
</table>
</div>
<div id="Layer5">
<table width="507" height="49">
<tr>
<td width="15"><img src="Images/greendot.gif" width="11" height="13" /></td>
<td width="183"> </td>
<td width="200"> </td>
<td width="89"><label>
<input type="submit" name="Submit3" value="购买" />
</label></td>
</tr>
</table>
</div>
<table width="938" height="226">
<tr>
<td><div align="center">
<jsp:include page="Top.jsp"/>
<img src="Images/index_10.gif" width="957" height="52" />
<jsp:include page="Search.jsp"/>
<marquee direction=left TrueSpeed scrollAmount=2
scrollDelay=80 height=20
width=500 border="0">
<div align="left">欢迎光临明日网上书店，希望您能购买到称心如意的经典书籍！客服电话：13520086868，QQ：460925684。</div>
</marquee> </div></td>
</tr>
<tr>
<td><table width="100%" height="330">
<tr>
<td width="223"><jsp:include page="Left.jsp"/></td>
<td width="10" height="330"><div align="center"><img src="Images/tilel.gif" width="2" height="400" /></div></td>
<td> </td>
</tr>
</table></td>
</tr>
</table>
</body>
</html>
这是源程序，老是出错啊
<jsp:useBean id="dbO" scope="page" class="beans.DBoperation"/>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<link rel="stylesheet" href="CSS/style.css" type="text/css" media="screen">
<style type="text/css">
<!--
#Layer1 {
position:absolute;
left:102px;
top:1132px;
width:972px;
height:40px;
z-index:1;
}
#Layer2 {
position:absolute;
left:350px;
top:633px;
width:186px;
height:477px;
z-index:2;
}
#Layer3 {
position:absolute;
left:580px;
top:640px;
width:519px;
height:27px;
z-index:3;
}
#Layer4 {
position:absolute;
left:556px;
top:685px;
width:512px;
height:38px;
z-index:4;
}
#Layer5 {
position:absolute;
left:559px;
top:735px;
width:508px;
height:51px;
z-index:5;
}
-->
</style>
</head>
<%
String condition = "SELECT DISTINCT Type FROM tb_Bookinfo ";
ResultSet rs_type = dbO.executeQuery(condition);
%>
<body>
<div id="Layer1"><jsp:include page="Tail.jsp"/></div>
<div id="Layer2">
<table width="188" height="84">
<tr>
<td height="36" colspan="2" background="Images/bg_booksort.gif">
<table width="174">
<tr>
<td width="42"><div align="right"><img src="Images/ico_booksort.gif" width="25" height="25" /></div></td>
<td width="120">图书分类列表</td>
</tr>
</table></td>
</tr>
<%while(rs_type.next()){%>
<tr>
<td width="32" height="40"> <img src="Images/boardlist.gif" width="25" height="14" /></td>
<td width="144"><%=rs_type.getString(3)%></td>
</tr>
<%}%>
</table>
</div>
<div id="Layer3">
<table width="514" height="25">
<tr>
<td><div align="left">图书类别: [ ] </div></td>
</tr>
</table>
</div>
<div id="Layer4">
<table width="511" height="39">
<tr>
<td width="18"> </td>
<td width="182">书名</td>
<td width="205">出版社</td>
<td width="86">购买</td>
</tr>
</table>
</div>
<div id="Layer5">
<table width="507" height="49">
<tr>
<td width="15"><img src="Images/greendot.gif" width="11" height="13" /></td>
<td width="183"> </td>
<td width="200"> </td>
<td width="89"><label>
<input type="submit" name="Submit3" value="购买" />
</label></td>
</tr>
</table>
</div>
<table width="938" height="226">
<tr>
<td><div align="center">
<jsp:include page="Top.jsp"/>
<img src="Images/index_10.gif" width="957" height="52" />
<jsp:include page="Search.jsp"/>
<marquee direction=left TrueSpeed scrollAmount=2
scrollDelay=80 height=20
width=500 border="0">
<div align="left">欢迎光临明日网上书店，希望您能购买到称心如意的经典书籍！客服电话：13520086868，QQ：460925684。</div>
</marquee> </div></td>
</tr>
<tr>
<td><table width="100%" height="330">
<tr>
<td width="223"><jsp:include page="Left.jsp"/></td>
<td width="10" height="330"><div align="center"><img src="Images/tilel.gif" width="2" height="400" /></div></td>
<td> </td>
</tr>
</table></td>
</tr>
</table>
</body>
</html>
这是源程序，老是出错啊
zjsfdxbao 2007-05-07
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你写的没问题
