[SQL ] Invalid use of group function

[jami520 (我的生命因你而發光)]

請問這樣寫有錯嗎?

SELECT sid, bid, SUM(num) FROM mydbtable WHERE gdate>=
'2013-02-18' and gdate<= '2013-02-22' and SUM(num)/SUM(num/percentage)>0.05
GROUP BY concat(binary bid)

附註:sid, bid, num, percentage為table欄位

產生的錯誤為Invalid use of group function
找了很久，不曉得是哪邊錯誤呢?

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◆ From: 219.71.217.130
推 icydream:select的欄位，與group by的欄位不符
→ icydream:改為select concat(binary bid), sum(num)試試，
→ icydream:或是再重新調整group by的欄位。