根据jsp中的输入选择表

Question

我在mysql数据库中有两张表，一张给学生，一张给老师。两个表具有相同的列。

下面的代码只将数据插入到教师表中。如果用户选择教师单选按钮，则注册数据应存储在教师表中。如果用户选择学生电台，则注册数据应存储在学生表中。对此有什么解决方案？

enter image description here

index.jsp

<form  method="GET " action="statement2.jsp" autocomplete="on"> 
  <input type="radio" name="gender" value="Teacher" checked/> Teacher
  <input type="radio" name="gender" value="Student"/>Student
  <input type="submit" value="Login" /> 
  <input type="button" onclick="location.href='reg.jsp';" value="Sign Up" />
</form>

---

statement2.jsp

<%
   String name=request.getParameter("first");
   String abc=request.getParameter("last");
   String cde=request.getParameter("user");
   String pass=request.getParameter("password");
   String confpass=request.getParameter("confirmpass");
   String emails=request.getParameter("email");
   String months=request.getParameter("month");
   String day=request.getParameter("day");
   String year=request.getParameter("year");
   String gender=request.getParameter("gender");

   String Sql="insert into teacher2(firstname,lastname,username,password,confirmpassword,email,month,day,year,gender) values('"+name+"','"+abc+"','"+cde+"','"+pass+"','"+confpass+"','"+emails+"','"+months+"','"+day+"','"+year+"','"+gender+"')";
   st.executeUpdate(Sql);
%>

修正后 statement2.jsp

<%
   String name=request.getParameter("first");
   String abc=request.getParameter("last");
   String cde=request.getParameter("user");
   String pass=request.getParameter("password");
   String confpass=request.getParameter("confirmpass");
   String emails=request.getParameter("email");
   String months=request.getParameter("month");
   String day=request.getParameter("day");
   String year=request.getParameter("year");
   String gender=request.getParameter("gender");

   if (gender != null) {
   String table = gender.equals("teacher") ? "teacher2" : "student";
   // replace dots with your values
   String query = "INSERT INTO " + table + "(firstname,lastname,username,password,confirmpassword,email,month,day,year,gender) VALUES ('"+name+"','"+abc+"','"+cde+"','"+pass+"','"+confpass+"','"+emails+"','"+months+"','"+day+"','"+year+"','"+gender+"')";

   st.executeUpdate(query); 
  %>

---

这个查询出了什么问题。为什么这个查询只在一张学生表中插入数据

index.jsp

   <input type="radio" name="gender" value="teacher" checked/> Teacher
   <input type="radio" name="gender" value="Student"/>Student

statement2.jsp

   String gender = request.getParameter("gender");
   if (gender != null) {
   String table = gender.equals("teacher") ? "teacher2" : "student";
// replace dots with your values
   String query = "INSERT INTO " + table + "(firstname,lastname,username,password,confirmpassword,email,month,day,year,gender) VALUES ('"+name+"','"+abc+"','"+cde+"','"+pass+"','"+confpass+"','"+emails+"','"+months+"','"+day+"','"+year+"','"+gender+"')";
  st.executeUpdate(query);

Answer 1

只需选择一个合适的表，然后将其传递给您的查询语句

<%
  String gender = request.getParameter("gender");
  if (gender != null) {
    String table = gender.equals("teacher") ? "teacherTable" : "studentTable";
    // replace dots with your values
    String query = "INSERT INTO " + table + "(...) VALUES (...)";
    st.executeUpdate(query); 
  }
%>

请注意，重定向到另一个 jsp 并在那里使用脚本（规范不鼓励）处理提交的数据并不是最佳选择。我宁愿建议您将表单提交到 Servlet 并在那里编写所有 Java 代码。

您可能还想看看PreparedStatement 而不是Statement。

如果您有兴趣，请查看这些答案

How to avoid Java code in JSP files?

When should we use a PreparedStatement instead of a Statement?