我有一列“小时” 我有一列“那种”(也可以是1,2或3)MySql:是否可以'SUM IF'或'COUNT IF'?
我想这样做:
SELECT count(id), SUM(hour) as totHour, SUM(IF (kind = 1, 1, 0)) as countKindOne
或
SELECT count(id), SUM(hour) as totHour, COUNT(IF (kind = 1)) as countKindOne
但是,mysql告诉我我有一个错误...什么是错误!?
请参阅本计算器话题:MySQL SUM IF field b = field a
..我不能回答这个...
我投了SUM(kind = 1)。简洁,清晰,直观.... – Delmo
非常有用的+1从我,,,,谢谢 –
SUM(kind = 1)非常简单。从我的+1 – vhen