查询条件写得不对吗？

Question

该代码段能正常显示所有记录，但按姓名查或按职称（下拉式列表）或按部门（下拉式列表）时均查不到记录，请问代码该如何修改呢？另外”修改“两个字怎么不是超链接的样式？      String sqlString=" ";
      String teacherName=request.getParameter("teacherName");
      String technicalPosition=request.getParameter("technicalPositionSelect");
      String department=request.getParameter("departmentSelect");
       
     
      if(request.getParameter("teacherName")!=null && request.getParameter("teacherName")!="") 
   {  
     sqlString=sqlString+ "and T_name='teacherName'";
   }
      if(request.getParameter("technicalPositionSelect")!=null&&request.getParameter("technicalPositionSelect")!="")
   {
       sqlString=sqlString + " and T_technicalposition='technicalPosition'";
   }
      if(request.getParameter("departmentSelect")!=null&&request.getParameter("departmentSelect")!="")
   {
       sqlString=sqlString + " and T_department='department'";
   }
  
ResultSet rs=db.executeQuery("select * from teacher "
                           +" where 1=1 "
                           +sqlString+" order by T_name desc "
        String teacherId="";
while(rs.next())
{

        teacherId=rs.getString("Id");
out.println("<tr height=22>");
out.println("<td align=center>"+rs.getString("T_name")+"</td>");
out.println("<td align=center>"+rs.getString("T_technicalposition")+"</td>");
out.println("<td align=center>"+rs.getString("T_department")+"</td>");
%>
<td align="center"<a href="teacherModify.jsp?teacherId=<%=teacherId%>">
修改</a>&nbsp;&nbsp;&nbsp;<a href="javascript:del('teacherManage.jsp',<%=teacherId%>)">删除</a></td></tr>
        }

Answer 1

此回复为自动发出,仅用于显示而已，并无任何其他特殊作用
楼主【hyxwxy】截止到2008-07-25 17:00:19的历史汇总数据(不包括此帖)：
发帖的总数量:15                       发帖的总分数:220                      每贴平均分数:14                       
回帖的总数量:24                       得分贴总数量:2                        回帖的得分率:8%                       
结贴的总数量:13                       结贴的总分数:200                      
无满意结贴数:0                        无满意结贴分:0                        
未结的帖子数:2                        未结的总分数:20                       
结贴的百分比:86.67 %               结分的百分比:90.91 %                  
无满意结贴率:0.00  %               无满意结分率:0.00  %                  
楼主加油

Answer 2

用LIKE试试吧
超连接不要放TD里或者换下条件，这么写
teacherName!=null&&teacherName.length()>0

Answer 3

<td align="center"<a href="teacherModify.jsp?teacherId=<%=teacherId%>">
错了
<td align="center"><a href="teacherModify.jsp?teacherId=<%=teacherId%>">修改</a>查不出来的原因是因为你这个sqlString初值是不是有个空格？所以最后的sql不正确了。
你在执行前把这句SQL打出来看看，可能拼错了。dubug一下吧。还有楼主的头像挺不错，我喜欢，呵呵。

Answer 4

主要还是SQL的关系，你用一个String把它存一下，然后debug显示一个，看看这句SQL能不能运行。
或者数据库中没有符合的记录。

Answer 5

空格去掉也不行，将String打出来看，是越来越长啊，最后成这个样子了  and T_name='teacherName' and T_name='teacherName' and T_technicalposition='technicalPosition' and T_name='teacherName' and T_technicalposition='technicalPosition' and T_department='department' 

Answer 6

      String sqlString=" ";
      String teacherName=request.getParameter("teacherName");
      String technicalPosition=request.getParameter("technicalPositionSelect");
      String department=request.getParameter("departmentSelect");
                         
                    
      if(request.getParameter("teacherName")!=null && request.getParameter("teacherName")!="") 
          {     
               sqlString=sqlString+ "and T_name='teacherName'";
          }
      if(request.getParameter("technicalPositionSelect")!=null&&request.getParameter("technicalPositionSelect")!="")
          {    
              sqlString=sqlString + " and T_technicalposition='technicalPosition'";
          }
      if(request.getParameter("departmentSelect")!=null&&request.getParameter("departmentSelect")!="")
          {    
              sqlString=sqlString + " and T_department='department'";
          }
    //你把这个sqlString的值复制下来放到你的数据库里去执行一下看看效果就知道了。
    sqlString = "select * from teacher where 1=1 " + sqlString + "orderby T_name desc";
    
    ResultSet rs=db.executeQuery(sqlString);

Answer 7

      String sqlString="";
      String teacherName=request.getParameter("teacherName");
      String technicalPosition=request.getParameter("technicalPositionSelect");
      String department=request.getParameter("departmentSelect");
                         
                    
      if(request.getParameter("teacherName")!=null && request.getParameter("teacherName")!="") {     
               sqlString=sqlString+ "and T_name='teacherName' ";
      }
      if(request.getParameter("technicalPositionSelect")!=null&&request.getParameter("technicalPositionSelect")!="") {    
              sqlString=sqlString + "and T_technicalposition='technicalPosition' ";
      }
      if(request.getParameter("departmentSelect")!=null&&request.getParameter("departmentSelect")!="") {    
              sqlString=sqlString + "and T_department='department' ";
      }    //你把这个sqlString的值复制下来放到你的数据库里去执行一下看看效果就知道了。
    sqlString = "select * from teacher where 1=1 " + sqlString + "order by T_name desc";
    
    ResultSet rs=db.executeQuery(sqlString);
拿我这个试试看，呵呵。将结果告诉我。