JDBC连接数据库查询表

1.添加需要的jar包(maven项目只用添加依赖即可自动下载jar包)

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.47</version>
</dependency>

2.

import java.sql.*;

public class JdbcDemo {
    public static void main(String[] args) throws ClassNotFoundException, SQLException {

        //1.加载驱动
        Class.forName("com.mysql.jdbc.Driver");


        //2. 用户信息和url
        String url = "jdbc:mysql://localhost:3306/mybatis?useSSL=true&useUnicode=true&characterEncoding=UTF-8";
        String username = "root";
        String password = "123456";
        //3.连接成功,数据库对象
        Connection connection = DriverManager.getConnection(url, username, password);

        //4.执行sql的对象
        Statement statement = connection.createStatement();

        //5.执行sql的对象去执行sql
        String sql = "SELECT * FROM USER";
        ResultSet resultSet = statement.executeQuery(sql);

        while (resultSet.next()){
            System.out.println("id"+ resultSet.getObject("id"));
            System.out.println("name"+ resultSet.getObject("name"));
            System.out.println("pwd"+ resultSet.getObject("pwd"));
        }
        //6.释放连接
        resultSet.close();
        statement.close();
        connection.close();
   }
}