Error No. 2003: Can't connect to MySQL server on 'localhost' (or some other host)

Error No. 2003: Can't connect to MySQL server on 'localhost' (or some other host)

    simply means that connection is not possible for one of the following (or similar) reasons:

1.There is no MySQL server running at the specified host

2.Connection to the MySQL server is not allowed using TCP-IP.

3. Some networking issue prevents connection.

4.When trying to connect to a MySQL server at an ISP this error message often indicates that direct connection to MySQL has been blocked.

出错原因主要是这4个，一般首先看的是mysql服务有没开启。安装时默认开机就启动的，那就不用考虑，如果自己改动过的就要注意下，我自己是关掉的，要手动开启。