在IDEA中使用JDBC

1.使用JDBC API 连接和访问数据库，一般分为以下5个步骤

(1)加载驱动程序

(2)建立连接对象

(3)创建语句对象

(4)获得SQL语句的执行结果

(5)关闭建立的对象，释放资源

package package_test;
import java.sql.*;
import java.util.Arrays;
import java.util.Scanner;

public class class_test {

    public static void main(String[] args) {
        ResultSet rs = null;
        Connection connection = null;
        PreparedStatement statement = null;
        try {
            //1,加载驱动
            Class.forName("com.mysql.jdbc.Driver");
            //2.创建连接

            connection = DriverManager.getConnection(
                    "jdbc:mysql://127.0.0.1:3306/test?useSSL=true&characterEncoding=utf-8",
                    "root",
                    "123456");
            System.out.println("创建连接成功");
            //3.写sql
            //根据数据库实际的表名写SQL语句
            String sql = "select * from user";
            //4.得到statement对象执行sql
            statement = connection.prepareStatement(sql);
            //5.得到结果集
            rs = statement.executeQuery();
            //6.处理结果集
            while (rs.next()) {
                System.out.println(rs.getInt(1));
                System.out.println(rs.getString(2));
            }

        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            //7.关闭
            if (rs != null) {
                try {
                    rs.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if (statement != null) {
                try {
                    statement.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if (connection != null) {
                try {
                    connection.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }

            System.out.println("关闭成功");
        }
    }
}