精華 帝國PHP系統CMS如何用一句mysql語句實現多表數據之和?
<p>很多時候在用帝國php系統建站的時候需要獲取所有數據表數據的總和,但是又只能用一句mysql語句實現,下面這句很實用。</p>
SELECT COUNT(AA.id) FROM (SELECT id FROM ecms_news UNION ALL SELECT id FROM ecms_xiazai UNION ALL SELECT id FROM ecms_photo UNION ALL SELECT id FROM ecms_download) AA;
上面語句在帝國php系統后臺無法使用,需要做一下修改。
SELECT COUNT(AA.id) as total FROM (SELECT id FROM ecms_news UNION ALL SELECT id FROM ecms_xiazai UNION ALL SELECT id FROM ecms_photo UNION ALL SELECT id FROM ecms_download) AA;
是不是很簡單,趕緊收藏起來吧。