您的查詢不包含指定表達式“ ID”作為聚合函數的一部分

Question

在MSAccess中，我有以下查詢。 當我嘗試運行查詢時，出現錯誤消息Your query does not include the specified expression "ID" as part of aggregate function因此找不到原因。 我的查詢有什么問題？

SELECT
   Count(t2.subjectid) AS CountOfsubjectid,
   t2.pname,
   (
      select
         max(outcometime) 
      from
         table1 t1 
      where
         t1.id = t2.id 
   )
   AS showntime 
FROM
   table2 AS t2 
WHERE
   t2.outcome = "accepted" 
GROUP BY
   t2.pname,
   t2.showntime;

更新（樣本數據）：

表格1：

ID  outcometime pname  outcome  subjectid
1   20181111    USB    shown    Ux1ku
1   20181113    USB    shown    Ux1ku
2   20181115    USB    shown    Tsn2f
3   20181116    USB    shown    O93nf
2   20181114    USB    shown    Tsn2f
2   20181112    USB    shown    Tsn2f

表2：

ID  outcometime pname       outcome     subjectid
1   20181118    USB         accepted    Ux1ku
2   20181119    USB         accepted    Tsn2f
3   20181117    USB         accepted    O93nf

所需結果：

pname     showntime     countofsubjectid
USB       20181113         1
USB       20181115         1
USB       20181116         1

還更新了示例數據。 那是錯的。 謝謝。

Answer 1

如果我理解正確，則需要這樣寫：

SELECT Count(t2.subjectid) AS CountOfsubjectid,
       t2.name,
       (select max(outcometime) 
        from table1 as t1 inner join
             table2 as tt2
             on t1.id = tt2.id
        where tt2.name = t2.name
      ) as showntime 
FROM table2 AS t2 
WHERE t2.outcome = "accepted" 
GROUP BY t2.name;

Answer 2

當前，您嘗試在封裝在聚合查詢中的SELECT子句中運行相關子查詢，然后在GROUP BY子句中按別名引用此子查詢。

考慮使用派生表首先使用子查詢運行單元級別，然后在外部主查詢中運行聚合。

SELECT 
    dt.pname,
    COUNT(subjectid) AS CountOfsubjectid,
    dt.showntime
FROM 
  (SELECT
         t2.subjectid
         t2.pname,
         (
            select
               max(outcometime) 
            from
               table1 t1 
            where
               t1.id = t2.id 
         )
         AS showntime 
   FROM
        table2 AS t2 
   WHERE
        t2.outcome = 'accepted'
  ) AS dt
GROUP BY
   dt.pname,
   dt.showntime;

然而，考慮避免低效率的相關子查詢的每一行表運行加盟上對匯總查詢MAX計算一次 ，然后再次運行聚集COUNT的主要水平。

SELECT
   t2.pname,
   COUNT(t.subjectid) AS CountOfsubjectid,
   agg.showntime 
FROM
   table2 AS t2 
INNER JOIN 
    (
     select 
        t1.id,
        max(outcometime) as showntime
     from
        table1 t1 
     group by 
        t1.id                     
     ) AS agg
  ON t2.id = agg.id
WHERE
   t2.outcome = 'accepted'    
GROUP BY
   t2.pname,
   agg.showntime;