test.jdbc

package com.hisoft.test.jdbc;

import com.hisoft.epetshop.util.JdbcUtil;

import java.sql.*;

/**
 * @program: epetShop-01
 * @description:
 * @author: wlg
 * @create: 2020-10-13 08:18:12
 **/
public class TestJdbc {

    public static void query() {
        final Connection connection = JdbcUtil.getConnection();
        //3.创建Statement或者PreparedStatement对象
        Statement stmt = null;
        ResultSet rs = null;
        try {
            stmt = connection.createStatement();
            //4.执行SQL语句
            rs = stmt.executeQuery("select * from petowner");
            while (rs.next()) {
                int id = rs.getInt(1);
                String name = rs.getString(2);
                String password = rs.getString(3);
                int money = rs.getInt(4);
                System.out.println(id + "\t" + name + "\t" + password + "\t" + money);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        //6.释放资源--Connection,Statement,ResultSet
        JdbcUtil.closeAll(connection, stmt, rs);
    }

    public static void add() {
        //1.加载驱动
        try {
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }

        //2.获取连接
        Connection connection = null;
        try {
            connection = DriverManager.getConnection("jdbc:mysql:///epetshop", "root", "root");
            System.out.println("连接成功");
        } catch (SQLException e) {
            e.printStackTrace();
        }

        //3.创建Statement或者PreparedStatement对象
        Statement stmt = null;
        try {
            stmt = connection.createStatement();
        } catch (SQLException e) {
            e.printStackTrace();
        }

        //4.执行SQL语句,增删改操作都使用executeUpdate方法,返回受影响的条数
        try {
            int count = stmt.executeUpdate("insert into petowner(name,password,money) values('郭靖','123456',300)");
            System.out.println("成功添加了" + count + "条记录");
        } catch (SQLException e) {
            e.printStackTrace();
        }

        //5.释放资源
        if (stmt != null) {
            try {
                stmt.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (connection != null) {
            try {
                connection.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

    }

    public static void update() {
        //1.加载驱动
        try {
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }

        //2.获取连接
        Connection connection = null;
        try {
            connection = DriverManager.getConnection("jdbc:mysql:///epetshop", "root", "root");
            System.out.println("连接成功");
        } catch (SQLException e) {
            e.printStackTrace();
        }

        //3.创建Statement或者PreparedStatement对象
        Statement stmt = null;
        try {
            stmt = connection.createStatement();
        } catch (SQLException e) {
            e.printStackTrace();
        }

        //4.执行SQL语句,增删改操作都使用executeUpdate方法,返回受影响的条数
        try {
            int count = stmt.executeUpdate("update petowner set name = '黄蓉',password = '654321',money = 500 where id = 3");
            System.out.println("成功修改了" + count + "条记录");
        } catch (SQLException e) {
            e.printStackTrace();
        }

        //5.释放资源
        if (stmt != null) {
            try {
                stmt.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (connection != null) {
            try {
                connection.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

    }

    public static void delete() {
        //1.加载驱动
        try {
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }

        //2.获取连接
        Connection connection = null;
        try {
            connection = DriverManager.getConnection("jdbc:mysql:///epetshop", "root", "root");
            System.out.println("连接成功");
        } catch (SQLException e) {
            e.printStackTrace();
        }

        //3.创建Statement或者PreparedStatement对象
        Statement stmt = null;
        try {
            stmt = connection.createStatement();
        } catch (SQLException e) {
            e.printStackTrace();
        }

        //4.执行SQL语句,增删改操作都使用executeUpdate方法,返回受影响的条数
        try {
            int count = stmt.executeUpdate("delete from petowner where id = 3");
            System.out.println("成功删除了" + count + "条记录");
        } catch (SQLException e) {
            e.printStackTrace();
        }

        //5.释放资源
        if (stmt != null) {
            try {
                stmt.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (connection != null) {
            try {
                connection.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

    }

    public static void main(String[] args) {
//        query();
//        add();
//        update();
        delete();
    }
}