事务管理

public class JDBCDemo_connection {
    public static void main(String[] args) throws Exception{
        //1.注册驱动
        Class.forName("com.mysql.jdbc.Driver");

        //2.获取链接
        String url = "jdbc:mysql://127.0.0.1:3306/db1?useSSL=false";
        String username = "root";
        String password = "1234";
        Connection conn = DriverManager.getConnection(url,username,password);//返回值

        //3.定义sql语句;
        String sql1 = "update account set money = 3000 where id = 1;";
        String sql2 = "update account set money = 3000 where id = 2;";

        //4.获取执行sql的对象 Statement
        Statement stmt = conn.createStatement();
        
        try {
            //开启事务
            conn.setAutoCommit(false);
            //5.执行sql
            int count1 = stmt.executeUpdate(sql1);//受影响的行数
            //6.处理结果
            System.out.println(count1);
            int i = 3 / 0;

            int count2 = stmt.executeUpdate(sql2);//受影响的行数
            //6.处理结果
            System.out.println(count2);

            //提交事务
            conn.commit();
        } catch (Exception throwables) {
            //回滚事务
            conn.rollback();
            throwables.printStackTrace();
        }

        //7.释放资源
        stmt.close();
        conn.close();
    }
}