SQL UPDATE 语句

  +----+--------------+---------------------------+-------+---------+

  | id | name | url | alexa | country |

  +----+--------------+---------------------------+-------+---------+

  | 1 | Google | https://www.google.cm/ | 1 | USA |

  | 2 | 淘宝 | https://www.taobao.com/ | 13 | CN |

  | 3 | 菜鸟学堂 | http://edu.jb51.net/ | 1689 | CN |

  | 4 | 微博 | http://weibo.com/ | 20 | CN |

  | 5 | Facebook | https://www.facebook.com/ | 3 | USA |

  +----+--------------+---------------------------+-------+---------+