java操作mysql的增删改查

prepareStatement(sql)是statement的子类，比statement好用。

如果数据库中定义的是int值，那么sql语句中要把int单独提出来。如".....values("+8329+","+34243+",'mm','789')"

下载java 数据库驱动jdbc，请戳这里http://pan.baidu.com/s/1sjPgT8T

package com.cn.edu;

import java.beans.Statement;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class helloworld {
    private Connection conn = null;
    PreparedStatement statement = null;

    // connect to MySQL
    void connSQL() {
        String url = "jdbc:mysql://localhost:3306/hello?characterEncoding=UTF-8";
        String username = "root";
        String password = "root"; // 加载驱动程序以连接数据库 
        try { 
            Class.forName("com.mysql.jdbc.Driver" ); 
            conn = DriverManager.getConnection( url,username, password ); 
            }
        //捕获加载驱动程序异常
         catch ( ClassNotFoundException cnfex ) {
             System.err.println(
             "装载 JDBC/ODBC 驱动程序失败。" );
             cnfex.printStackTrace(); 
         } 
         //捕获连接数据库异常
         catch ( SQLException sqlex ) {
             System.err.println( "无法连接数据库" );
             sqlex.printStackTrace(); 
         }
    }

    // disconnect to MySQL
    void deconnSQL() {
        try {
            if (conn != null)
                conn.close();
        } catch (Exception e) {
            System.out.println("关闭数据库问题 ：");
            e.printStackTrace();
        }
    }

    // execute selection language
    ResultSet selectSQL(String sql) {
        ResultSet rs = null;
        try {
            statement = conn.prepareStatement(sql);
            rs = statement.executeQuery(sql);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return rs;
    }

    // execute insertion language
    boolean insertSQL(String sql) {
        try {
            statement = conn.prepareStatement(sql);
            statement.executeUpdate();
            return true;
        } catch (SQLException e) {
            System.out.println("插入数据库时出错：");
            e.printStackTrace();
        } catch (Exception e) {
            System.out.println("插入时出错：");
            e.printStackTrace();
        }
        return false;
    }
    //execute delete language
    boolean deleteSQL(String sql) {
        try {
            statement = conn.prepareStatement(sql);
            statement.executeUpdate();
            return true;
        } catch (SQLException e) {
            System.out.println("插入数据库时出错：");
            e.printStackTrace();
        } catch (Exception e) {
            System.out.println("插入时出错：");
            e.printStackTrace();
        }
        return false;
    }
    //execute update language
    boolean updateSQL(String sql) {
        try {
            statement = conn.prepareStatement(sql);
            statement.executeUpdate();
            return true;
        } catch (SQLException e) {
            System.out.println("插入数据库时出错：");
            e.printStackTrace();
        } catch (Exception e) {
            System.out.println("插入时出错：");
            e.printStackTrace();
        }
        return false;
    }
    // show data in ju_users
    void layoutStyle2(ResultSet rs) {
        System.out.println("-----------------");
        System.out.println("执行结果如下所示:");
        System.out.println("-----------------");
        System.out.println(" 用户ID" + "/t/t" + "淘宝ID" + "/t/t" + "用户名"+ "/t/t" + "密码");
        System.out.println("-----------------");
        try {
            while (rs.next()) {
                System.out.println(rs.getInt("ju_userID") + "/t/t"
                        + rs.getString("taobaoID") + "/t/t"
                        + rs.getString("ju_userName")
                         + "/t/t"+ rs.getString("ju_userPWD"));
            }
        } catch (SQLException e) {
            System.out.println("显示时数据库出错。");
            e.printStackTrace();
        } catch (Exception e) {
            System.out.println("显示出错。");
            e.printStackTrace();
        }
    }

    public static void main(String args[]) {

        helloworld h = new helloworld();
        h.connSQL();
        String s = "select * from ju_users";

        String insert = "insert into ju_users(ju_userID,TaobaoID,ju_userName,ju_userPWD) values("+8329+","+34243+",'mm','789')";
        String update = "update ju_users set ju_userPWD =123 where ju_userName= 'mm'";
        String delete = "delete from ju_users where ju_userName= 'mm'";

        if (h.insertSQL(insert) == true) {
            System.out.println("insert successfully");
            ResultSet resultSet = h.selectSQL(s);
            h.layoutStyle2(resultSet);
        }
        if (h.updateSQL(update) == true) {
            System.out.println("update successfully");
            ResultSet resultSet = h.selectSQL(s);    
            h.layoutStyle2(resultSet);
        }
        if (h.insertSQL(delete) == true) {
            System.out.println("delete successfully");
            ResultSet resultSet = h.selectSQL(s);
            h.layoutStyle2(resultSet);
        }
        
        h.deconnSQL();
    }
}