在eclipse中使用servlet jsp在同一个数据库表中插入多行

Question

我正在尝试在提交时在同一个数据库中插入多行（每行有很多字段），但无法这样做。我能够成功插入单行，但是当涉及多行时，我被卡住了。

这是一个 jsp 页面，您可以在其中接受输入以动态添加行数。每行没有单独的提交按钮，而是单个提交按钮来插入所有行。

1.> projmgrsuccessful.jsp

<form name="allocate-project-task" action="AddProjectTaskDAO" method="get"  enctype="multipart/form-data">
<h4>Another popup</h4>
<input type="hidden" name="proj_emp_comt" value="">
<input type="hidden" name="pid" value="<c:out value="${pid}" />">

<label>Enter the no of employee involved in project</label>
<input type="text" id="textbox1" />
<input type="button" value="Add" id="add" />

<table border="1" id="pt-tabledata">
</table>

<center><input type="submit" name="alloc_time" value="Allocate"><a href="#"  id="closea">Close</a></center>
</form>
<script>
$("#add").click(function() {
$('#pt-tabledata').append('<tr><td>Username</td><td>Work description</td> <td>Allocate time</td><td>Allocate work and time</td></tr>');
for (var i = 0; i < $("#textbox1").val(); i++) {
    $newdiv2 = $('<tr id="pt-ip-row" style="display:block;"><td><select name="uname"><c:forEach items="${ual}" var="u"><option value="<c:out value="${u.uname}"></c:out>"><c:out value="${u.uname}"></c:out></option> </c:forEach>              </select></td><td><textarea rows="5" cols="15" name="pdesc_emp"></textarea></td><td><input type="text" name="pestd_time_alloc" /></td><td></td><td><a href="#" id="close-pt-row" onclick="return hide();">Close</a></td> </tr>').after("#add");
    $('#pt-tabledata').append($newdiv2);
}
});
</script>

这是 java 代码 sn-p，我在其中处理数据，例如连接到数据库并将其插入到数据库表中。

2.> AddProjectTaskDAO.java

package com.pms.servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection; 
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.Statement;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
* Servlet implementation class AddProjectTaskDAO
*/
@WebServlet("/AddProjectTaskDAO")
public class AddProjectTaskDAO extends HttpServlet {
private static final long serialVersionUID = 1L;

/**
 * @see HttpServlet#HttpServlet()
 */
public AddProjectTaskDAO() {
    super();
    // TODO Auto-generated constructor stub
}

/**
 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
 */
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    // TODO Auto-generated method stub

    response.setContentType("text/html");  
    PrintWriter pw = response.getWriter(); 

    Connection conn=null;
    String url="jdbc:mysql://localhost:3306/";
    String dbName="projectmanagement";
    String driver="com.mysql.jdbc.Driver";
    String dbUsername="root";
    String dbPassword="root";

    try{  

          String Projid=" ";
          String Projuname=" ";
          String Projdesc_emp=" ";
          String Projestd_time_alloc=" ";
          String Projtask_emp_comment=" ";
          String Pid[] = request.getParameterValues("pid");  
          String Uname[] = request.getParameterValues("uname");  
          String Pdesc_emp[] = request.getParameterValues("pdesc_emp"); 
          String Pestd_time_alloc[] =  request.getParameterValues("pestd_time_alloc");
          String Projtask_emp_cmnt[] = request.getParameterValues("ptask_emp_cmnt");  
          //String Utype = request.getParameter("utype");

          for(int i=0; i<100; i++){
              Projid=Pid[i]+" "+ 1;
              Projuname=Uname[i]+" "+ 1;
              Projdesc_emp=Pdesc_emp[i]+" "+ 1;
              Projestd_time_alloc=Pestd_time_alloc[i]+" "+ 1;
              Projtask_emp_comment=Projtask_emp_cmnt[i]+" "+ 1;
              }

          Class.forName(driver);  
          conn = DriverManager.getConnection(url+dbName,dbUsername, dbPassword);
          Statement st=conn.createStatement();


          int i = st.executeUpdate("insert into projtaskallocate (pid,uname,ptdesc_emp,ptestd_time_alloc,ptask_emp_cmnt) values ('" +Projid+ "','" +Projuname+"','" +Projdesc_emp+ "','" +Projestd_time_alloc+ "','" +Projtask_emp_comment+ "')");

          String msg=" ";
          if(i!=0){  
          UserPMDAO dd = new UserPMDAO();
          request.setAttribute("ual", dd.getUsers());
          ProjectDAO pp = new ProjectDAO();
          request.setAttribute("pal", pp.getProjects());  
          String nextJSP = "/projmgrsuccessful.jsp"; 
          RequestDispatcher dispatcher = getServletContext().getRequestDispatcher(nextJSP); 
          dispatcher.forward(request,response);



          }  
          else
          {  
              msg="Failed to Add Project";
              pw.print("<font size='6' color=blue>" + msg + "</font>");
          }  
          pw.close();
          //pst.close();
          st.close();
          conn.close();
        }  
        catch (Exception e)
        {  
        e.printStackTrace(); 
        }  

}

/**
 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
 */
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    // TODO Auto-generated method stub



}

}

这里的问题是当我点击提交按钮时只插入第一行，但我的要求是插入所有行。

请帮助，如果我出错了，请指导我。

Answer 1

您可以使用 Batch 语句使用 jdbc 插入多行，

for (int i=0:i<100;i++) {
    String query = "insert into projtaskallocate (pid,uname,ptdesc_emp,ptestd_time_alloc,ptask_emp_cmnt) values ('" +Projid+ "','" +Projuname+"','" +Projdesc_emp+ "','" +Projestd_time_alloc+ "','" +Projtask_emp_comment+ "')";
    statement.addBatch(query);
}
statement.executeBatch();
statement.close();
connection.close();

希望对你有帮助！！

Answer 2

问题出在你的 for 循环中。每次迭代都会覆盖从参数数组读取的值，并且变量将只有最后一个元素值。使用下面的代码。

    conn = DriverManager.getConnection(url+dbName,dbUsername, dbPassword);

    String query = "insert into projtaskallocate (pid,uname,ptdesc_emp,ptestd_time_alloc,ptask_emp_cmnt) values (?,?,?,?,?)";

    PreparedStatement pstmt = conn.prepareStatement(query);

    for(int i=0; i<100; i++){

         Projid=Pid[i]+" "+ 1;

         Projuname=Uname[i]+" "+ 1;

         --

         --

         pstmt.setString(1, Projid);

         pstmt.setString(2, Projuname);

         --

         --

         pstmt.addBatch();

    }

    pstmt.executeBatch();

http://www.mkyong.com/jdbc/jdbc-preparedstatement-example-batch-update/