做一个查询数据库的功能，表tellist中分别有name,sex,age,tel,mail,adr字段，查询页面有一个下拉框，是按哪个字段查询，一个表单输入查询内容，代码如下：
public String Query(HttpServletRequest request){
String html="";
String sql="select * from tellist";
String type=request.getParameter("type");
String content=request.getParameter("content");
if(type.equals("name"))
sql+="where name=?";
if(type.equals("sex"))
sql+="where sex=?";
if(type.equals("age"))
sql+="where age=?";
if(type.equals("tel"))
sql+="where tel=?";
if(type.equals("mail"))
sql+="where mail=?";
if(type.equals("adr"))
sql+="where adr=?";
try{
PreparedStatement pstmt=con.prepareStatement(sql);
pstmt.setString(1,content);
ResultSet rs1=pstmt.executeQuery(sql);
html+="
| 姓名 | 性别 | 年龄 | 电话 | 邮箱 | 住址 |
| "; html+=rs1.getString("name"); html+=" | ";"; html+=rs1.getString("sex"); html+=" | ";"; html+=rs1.getString("age"); html+=" | ";"; html+=rs1.getString("tel"); html+=" | ";"; html+=rs1.getString("mail"); html+=" | ";"; html+=rs1.getString("adr"); html+=" | ";
}
catch(Exception e){
e.printStackTrace();
}
return html;
}
总报错，如下：
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '=?' at line 1
；但是我没发现我的SQL语句有错啊，求大神解答！
