java连接myql步骤

步骤:加 连 欲 执 释

加载驱动

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

创建连接

{callout color="#f0ad4e"} url 统一资源定位 jdbc:mysql://主机名:服务器端口号 {/callout}

String url = "jdbc:mysql://127.0.0.1:3306/db3";
String username = "root";
String password = "12345678";
Connection connection = DriverManager.getConnection(url, username, password);

3.创建欲执行sql语句的对象 定义sql语句

String sql = "SELECT * FROM `emp`";
PreparedStatement statement=connection.prepareStatement(sql);

执行Resulit 结果集

ResultSet resultSet=statement.executeQuery();

释放连接

resultSet.close();
statement.close();

完整的代码

public class *** {
//查询用户数据列表方法测试
@Test
public void opreatedsql() throws Exception{
//jdbc 操作数据库查询列表  加 连  欲 执 释
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://127.0.0.1:3306/db3";
String username = "root";
String password = "12345678";
Connection connection = DriverManager.getConnection(url, username, password);
String sql = "SELECT * FROM `emp`";
PreparedStatement statement=connection.prepareStatement(sql);
ResultSet resultSet=statement.executeQuery();
resultSet.close();
statement.close();
}
}