查询表达式中的语法错误（逗号）。 MS Access 2013

Question

我在Access 2013中建立一个SQL查询。这是我的查询：

SELECT  
COUNT(Age) FROM Members AS [Under 12] WHERE Age <= 12,
COUNT(Age) FROM Members AS [13-18] WHERE Age BETWEEN 13 AND 18

但我不断收到此错误：

查询表达式'Age <= 12，来自SukkotMembers AS [13-18]年龄在13和18之间的语法错误（逗号）`

问题出在第二行末尾的逗号，但是我不明白为什么。 当我只运行一行时，它工作正常。 我对SQL真的很陌生，请注意。

我也刚刚意识到AS [Under 12]和AS [13-18]无法正常工作，我也不知道为什么

Answer 1

第一：您使用的语法不是有效的SQL，因为您有多个不允许的FROM子句； 这同样适用于where子句，该子句对整个集合进行操作。

您不能仅将SQL的零碎片段和补丁打成一片，以得到有效的查询-必须遵守一个相当严格且定义明确的语法。

您想要的是使用返回标量值的子查询或使用条件计数：

SELECT  
  COUNT(IIF(Age<=12,age,null)) AS [Under 12] 
 ,COUNT(IIF(Age BETWEEN 13 AND 18,age,null)) AS [13-18]  
FROM Members

同样， FROM Members AS [13-18]为表而不是列分配别名。

使用子查询（我想这可能是您的意图）：

SELECT DISTINCT
    (SELECT COUNT(*) FROM MEMBERS WHERE AGE<=12) AS  [UNDER 12] ,
    (SELECT COUNT(*) FROM MEMBERS WHERE AGE BETWEEN 13 AND 18) AS  [13-18]
FROM MEMBERS

Answer 2

您还可以总结：

SELECT  
    Sum(Abs(Age <= 12)) AS [Under 12],
    Sum(Abs(Age BETWEEN 13 AND 18)) AS [13-18]  
FROM 
    Members