package cn.wh.jdbc.test;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

/**

 * JdbcTest.java 简单的jdbc编程步骤过程

 */

public class JdbcTest {

    public static void main(String[] args) {

        Connection connection = null;

        PreparedStatement preparedStatement = null;

        ResultSet resultSet = null;

        try {

            // 1.加载数据库驱动

            Class.forName("com.mysql.jdbc.Driver");

            // 2.创建数据库连接

            connection = DriverManager.getConnection(

                    "jdbc:mysql://localhost:3306/mybatis?characterEncoding=utf-8",

                    "root", "1234");

            // 3.书写sql语句

            String sql = " select * from user where username=? ";

            // 4.创建statement,预处理sql语句

            preparedStatement = connection.prepareStatement(sql);

            // 5.设置sql里的参数

            preparedStatement.setString(1, "张三");

            // 6.执行sql,得到结果集

            resultSet = preparedStatement.executeQuery();

            // 7.遍历结果集，打印输出

            while (resultSet.next()) {

                System.out.println(resultSet.getString("id") + " "

                        + resultSet.getString("username"));

            }

        }

        catch (Exception e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

        finally {

            // 8.释放资源

            if (resultSet != null) {

                try {

                    resultSet.close();

                }

                catch (SQLException e) {

                    // TODO Auto-generated catch block

                    e.printStackTrace();

                }

            }

            if (preparedStatement != null) {

                try {

                    preparedStatement.close();

                }

                catch (SQLException e) {

                    // TODO Auto-generated catch block

                    e.printStackTrace();

                }

            }

            if (connection != null) {

                try {

                    connection.close();

                }

                catch (SQLException e) {

                    // TODO Auto-generated catch block

                    e.printStackTrace();

                }

            }

        }

    }

}