Question

我在JSP中创建了一个表单，用于在德比中将数据插入到数据库中，但它不起作用。

数据库名称为CUSTOMER。表格：

ID (int), CNAME (varchar), ADDRESS (varchar), PHONENUMBER (varchar)

client.jsp的内容：

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<jsp:useBean id="client" class="database.client" scope="page" />
<!DOCTYPE html>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>JSP Page</title>
</head>
<body bgcolor="lightgrey">
    <%
        String ID=request.getParameter("ID");
        String NAME=request.getParameter("CNAME");
        String ADDRESS=request.getParameter("ADDRESS");
        String PHONENUMBER=request.getParameter("PHONENUMBER");
    %>
    <form method="post" action="">
    <table border="0" align="left">
        <tr>
            <td>Name</td>
            <td><input type="text" name="CNAME" style="background-color:beige"/></td>
        </tr>
        <tr>
            <td>Address</td>
            <td><input type="text" name="ADDRESS" style="background-color:beige"/></td>
        </tr>
        <tr>
            <td>TelNumber</td>
            <td><input type="text" name="PHONENUMBER" style="background-color:beige"/></td>
        </tr>
            <input type="submit" name="OK" onclick="
                <%
               if(NAME!=null && ADDRESS!=null && PHONENUMBER!=null){
                    client.newClient(NAME, ADDRESS, PHONENUMBER);
                }
                %>" value="OK"/>
    </table>
</form>  
</body>

client.java的内容。

package database;

public class Client implements DatabaseConnection{

private static Connection conn = null;

private static void createConnection(){
try {
  conn = DriverManager.getConnection(URL, USER, PASSWORD);
} catch (SQLException ex) {
  Logger.getLogger(client.class.getName()).log(Level.SEVERE, null, ex);
}
}

private static void closeConnection(){
if (conn != null){
  try {
    conn.close();
  } catch (SQLException ex) {
    Logger.getLogger(client.class.getName()).log(Level.SEVERE, null, ex);
  }
}
}

public void newClient(String name, String address, String phoneNumber){
    try {
        createConnection();
        String insert="INSERT INTO CUSTOMER(CNAME,ADDRESS, PHONENUMBER) VALUES(?,?,?)";
        PreparedStatement ps=conn.prepareStatement(insert);
        ps.setString(2, name);
        ps.setString(3, address);
        ps.setString(4, phoneNumber);
        ps.executeUpdate();
        ps.close();
    } catch (Exception e) {

    }
}    
}

databaseConnection的内容。

package database;

public interface DatabaseConnection{
String URL="jdbc:derby://localhost:1527/Test";
String USER="myusername";
String PASSWORD="mypassword"; 
}

修改

错误消息：

Caused by: org.apache.derby.client.am.SqlException: Column position '4' is 
outside the allowed range. The columns of ResultSet are '3'.
Org.apache.derby.client.am.ColumnMetaData.checkForValidColumnIndex (unknown 
source)

EDIT2

public void deleteClient(String ID){
    try {
        String delete="DELETE FROM CUSTOMER WHERE ID=?";
        PreparedStatement ps=conn.prepareStatement(delete);
        ps.setString(1, ID);
        ps.executeUpdate();
    } catch (Exception e) {
    }
}

Answer 1

您的preparedStatement索引应该从1开始，而不是从2开始，所以请尝试

public void newClient(String name, String address, String phoneNumber){
    PreparedStatement ps = null;
    try {
        createConnection();
        String insert="INSERT INTO CUSTOMER(ID,CNAME,ADDRESS, PHONENUMBER) VALUES(?,?,?,?)";
        ps=conn.prepareStatement(insert);
        ps.setString(1, name);
        ps.setString(2, address);
        ps.setString(3, phoneNumber);
        ps.executeUpdate();
    } catch (Exception ex)  {
        ex.printStackTrace();
    } finally  {
        ps.close();
        closeConnection();
    }
}

PreparedStatement或Connection close方法应该在try catch finally块的最后部分。

与closeConnection()方法类似，您可以创建另一个方法来关闭preparedStatement并在finally块中调用它。

更新1

如果您在Java中捕获Id，请尝试

public void newClient(Integer id, String name, String address, String phoneNumber){
    PreparedStatement ps = null;
    try {
        createConnection();
        String insert="INSERT INTO CUSTOMER(CNAME,ADDRESS, PHONENUMBER) VALUES(?,?,?)";
        ps=conn.prepareStatement(insert);
        ps.setInt(1, id)
        ps.setString(2, name);
        ps.setString(3, address);
        ps.setString(4, phoneNumber);
        ps.executeUpdate();
    } catch (Exception ex)  {
        ex.printStackTrace();
    } finally  {
        ps.close();
        closeConnection();
    }
}

在JSP中，修改为

if(ID!=null && NAME!=null && ADDRESS!=null && PHONENUMBER!=null){
                    client.newClient(ID, NAME, ADDRESS, PHONENUMBER);
                }

如何在JSP中将值插入数据库到derby？

1 个答案: