idea 连接mysql数据库失败,不知道什么原因,求解决方法
```java
package com.itheima.jdbc;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;
public class JDBCDemo {
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";
String username="root";
String password="123456";
Connection conn = DriverManager.getConnection(url, username, password);
//3.定义sql
String sql="update account set money = 2000 where id = 1;";
//4.获取sql对象
Statement stmt=conn.createStatement();
//5.执行sql
int count=stmt.executeUpdate(sql);
//6.处理结果
System.out.println(count);
//7.释放资源
stmt.close();
conn.close();
}
}
```