MySQL的計數語句錯誤 - 操作數應包含1列（S）

Question

我試圖做多計數大家正在接受第一子選擇（列表1）我得到的，上面寫着「操作數應包含1列（或多個）錯誤「我猜它與AND有關，但我不確定我會如何解決這個問題。

Select Count(list0.ustatus) AS finished_count 
     , (Select list1.ustatus, Count(*) 
       From listofupdates list1 
      Where list1.ustarted != '0000-00-00 00:00:00' 
       AND list1.ustatus != 1 
      ) AS start_count 
     , (Select Count(list2.udifficulty) 
       From listofupdates list2 
      Where list2.udifficulty = 2 
      ) AS recheck_count 
     , (Select Count(list3.udifficulty) 
       From listofupdates list3 
       Where list3.udifficulty = 4 
      ) AS question_count 
    From listofupdates as list0 
    Where list0.ustatus = 1 

Answer 1

我完全@Chad樺木

aggree以下查詢應該工作。

Select Count(list0.ustatus) AS finished_count 
     , (Select Count(*) 
       From listofupdates list1 
      Where list1.ustarted != '0000-00-00 00:00:00' 
       AND list1.ustatus != 1 
      ) AS start_count 
     , (Select Count(list2.udifficulty) 
       From listofupdates list2 
      Where list2.udifficulty = 2 
      ) AS recheck_count 
     , (Select Count(list3.udifficulty) 
       From listofupdates list3 
       Where list3.udifficulty = 4 
      ) AS question_count 
    From listofupdates as list0 
    Where list0.ustatus = 1 

Answer 2

問題的最有可能在所述線路與

FROM listofupdates LISTX

（其中X爲0，1，2，3）

這似乎是在這些情況下，只有list0，list1，list2，list3就足夠了。

Answer 3

在第一個子選擇中，您試圖選擇2列。您只需要選擇一個，除非您正在對結果進行比較，否則無法重新選擇多個列。

請參閱MySQL Docs - Subquery Errors。