Joomla 500-没有有效的数据库连接：MySQL服务器已消失

我在一个托管服务器中的joomla下有一个网站。直到昨天，天气一直很好。但从昨天开始，当我打开网站时，它给了我以下错误：

500 - No valid database connection:MySQL server has gone away SQL=SELECT a.*, CASE WHEN CHAR_LENGTH(a.alias) THEN CONCAT_WS(":", a.id, a.alias) ELSE a.id END as slug, CASE WHEN CHAR_LENGTH(cc.alias) THEN CONCAT_WS(":", cc.id, cc.alias) ELSE cc.id END as catslug FROM jos_content AS a INNER JOIN jos_categories AS cc ON cc.id = a.catid INNER JOIN jos_sections AS s ON s.id = a.sectionid WHERE a.state = 1 AND ( a.publish_up = '0000-00-00 00:00:00' OR a.publish_up <= '2012-03-04 17:59:41' ) AND ( a.publish_down = '0000-00-00 00:00:00' OR a.publish_down >= '2012-03-04 17:59:41' ) AND s.id > 0 AND a.access <= 0 AND cc.access <= 0 AND s.access <= 0 AND s.published = 1 AND cc.published = 1 ORDER BY a.created DESC LIMIT 0, 5

---

有什么问题吗？或者是主机中心出了问题？

将数据库类型从mysql更改为mysqli。

这意味着。。。数据库连接消失了；你不再有联系了。插座是一个ex插座。它存在的唯一原因是它的脚被钉在接口上。

Internal Server Error.

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, webmaster@mysite.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.