急,一个关于模糊查询的问题,求高手指教啊.(在线等待)

maihill 2006-04-05 12:42:14

正在编写一个高级查询时,遇到不能实现模糊查询的问题.这个Jsp代码如下:

<%@ page language="java" contentType="text/html; charset=gb2312"
pageEncoding="gb2312" import="com.jspdev.bean.*,java.util.*,java.io.*"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>Insert title here</title>
</head>
<jsp:useBean id="treatise" class="com.jspdev.bean.TreatiseBean" scope="page"></jsp:useBean>
<body>
<%!
public String trans(String chi)
{
String result = "";
byte temp[];
try
{
temp=chi.getBytes("iso-8859-1");
result = new String(temp);
}
catch(UnsupportedEncodingException e)
{
System.out.println (e.toString());
}
return result;
}

public String codeStringRandom(String s)
{
String result="%"+s+"%";
return result;
}
%>
<center>
<% //KeywordId是关键字。
String KeywordId=request.getParameter("keywordId");
//Rule是查询字段。
String Rule=request.getParameter("selection");
//TypeId判断查询的类型。(用模糊查询还是精确查询)
String TypeId=request.getParameter("typeid");
String Sql=null;
if(KeywordId.equals(""))
{
out.println("<tr>");
out.println("<td bgcolor=#0033FF scope=col>"+"<div aligncenter>"+"</div>"+"</td>");
out.println("</tr>");
out.println("<tr>");
out.println("<td bordercolor=#000000>"+"<div align=center>");
out.println("<p>"+"<br>");
out.println("查询错误！用户没有提供查询的数据或数据库出错。"+"<br>");
out.println("<br>");
out.println("</p>");
out.println("</div>"+"</td>");
out.println("</tr>");
out.println("</table>");
}
else
{
if(Rule.equals("TeacherName"))
{
Rule="Teacher_no";
}
else
{
if(Rule.equals("Stu"))
{
Rule="Stu_no";
out.println("<h1>"+"按学生名查询得"+"</h1>");
}
else
{
if(Rule.equals("Num"))
{
Rule="Number";
out.println("<h1>"+"按项目名查询得"+"</h1>");
}
}
}
out.println("<table width=80% border=1 bgcolor=#0099CC>");
out.println("<tr bgcolor=#009966 bordercolor=#990066>");
out.println("<td>"+"Number"+"</td>"+"<td>"+"Subject"+"</td>"+"<td>"+"Putin"+"</td>"+"<td>"+"Guidance"+"</td>"+"<td>"+"StudentId"+"</td>"+"<td>"+"TeacherId"+"</td>");
out.println("</tr>");
if(TypeId.equals("Random"))
{
KeywordId=codeStringRandom(KeywordId);
}
KeywrodId=trans(KeywordId);
Sql=treatise.getSelection(Rule,KeywordId);
Collection treatises=treatise.getTreatiseforPro(Sql);
if(treatises.size()==0)
{
out.println("</table>");
out.println("没有数据"+"<br>");
}
else
{
Iterator it=treatises.iterator();
while(it.hasNext())
{
Treatise temp=(Treatise)it.next();
out.println("<tr bordercolor=#990066>");
out.println("<td>"+temp.getNumber()+"</td>");
out.println("<td>"+temp.getSubject()+"</td>");
out.println("<td>"+temp.getPutin()+"</td>");
out.println("<td>"+temp.getGuidance()+"</td>");
out.println("<td>"+temp.getStudentId()+"</td>");
out.println("<td>"+temp.getTeacherId()+"</td>");
out.println("</tr>");
}
out.println("</table>");
}
}
%>
<a href="index.html">Back</a>
</center>
</body>
</html>

它实现的JavaBean部分代码为:
public Collection getTreatiseforPro(String SQL)
{
Collection ret=null;
String condition=SQL;
try
{
Statement st=con.createStatement();
ResultSet rs=st.executeQuery(condition);
ret=new ArrayList();
while(rs.next())
{
Treatise temp=new Treatise();
temp.setNumber(rs.getString("Number"));
temp.setSubject(rs.getString("Subject"));
temp.setPutin(rs.getString("IsPutin"));
temp.setGuidance(rs.getString("IsGuidance"));
temp.setStudentId(rs.getString("Stu_no"));
temp.setTeacherId(rs.getString("Teacher_no"));
ret.add(temp);
}
con.close();
}
catch(Exception e){
e.getMessage();
}
return ret;
}

public String getSelection(String Rule,String KeyWord)
{
String rule=Rule;
String keyword=KeyWord;
String sql=null;
if(rule.trim().equals("Teacher_no"))
{
sql="select * from Treatise where "+rule+" = (select "+rule+" from Teachers where Name like '"+keyword+"')";
}
else
{
if(rule.trim().equals("Stu_no"))
{
sql="select * from Treatise where "+rule+"=(select "+rule+" from Students where Name like '"+keyword+"')";
}
else
{
sql="select * from Treatise where "+rule+"=(select "+rule+" from Treatise where Subject like '"+keyword+"')";
}
}
return sql;
}

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maihill 2006-04-07

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各位高手,请教教小弟吧

gefengxztg 2006-04-07

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为什么喜欢用else{if(){ }}这种句子啊
可能是我没读懂你的程序，是不是就是else if(){}啊

peijihui 2006-04-07

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强，这么长，怎么看啊

xiongbing528 2006-04-07

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看我的眼花啊。。

leojay1 2006-04-07

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是不是没有用通配符哟？

yyfhz 2006-04-06

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那你在JSP里把getSelection的返回值贴出来看看啊

maihill 2006-04-06

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输出的SQL语句就如:select * from Treatise where Teacher_no = (select Teacher_no from Teachers where Name like '木')
没有执行了这个语句
if(TypeId.equals("Random"))
{
KeywordId=codeStringRandom(KeywordId);
}

zh029t 2006-04-06