java - 空值存储mysql

Question

当我尝试使用 servlet 从 html 字段中保存数据时，正在存储空值。

我已经采取了字段，但两个字段都将 null 保存到表中。

import java.sql.SQLException;

public class Db_Connections {

    static UserDetails userdetails = new UserDetails();

    //static Connection conn=null;

    public static Connection conn() {
        Connection conn=null;

        try {
            Class.forName("com.mysql.jdbc.Driver");
             conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/skyhacker","root","root");
        } catch (Exception e) {
            e.printStackTrace();
        }
        return conn;
    }

    public static boolean insert_query(UserDetails userdetails2) {
        try {
            Connection conn =Db_Connections.conn();

            PreparedStatement pstmt_insert = conn.prepareStatement("insert into userdata values(?,?,?)");

            pstmt_insert.setInt(1 , userdetails.getId() );
            pstmt_insert.setString(2, userdetails.getName());
            pstmt_insert.setString(3, userdetails.getEmail());
            pstmt_insert.executeUpdate();

标签： javamysqlnull

Answer 1

方法的参数insert_query是userdetails2. 但是，当您将数据插入数据库时​​，您会从userdetails. 所以换上试试userdetails。userdetails2