MS Access 的计数问题

Question

以下查询在 MS Access 中运行良好，但我实际上只想获取 Main Project 字段加上 Name 的计数。比如：

SELECT Sheet1.[Main project], Count(Sheet1.[Name]) AS Total

当我这样做时，我收到以下错误：

“您尝试执行的查询不包含指定表达式'主项目'作为聚合函数的一部分'

我在连接中做错了吗？知道什么是不正确的吗？

SELECT Sheet1.[Main project], Sheet1.[Main link], Sheet1.[Name]
FROM Sheet1
INNER JOIN Sheet1 AS Sheet1_1 

ON (Sheet1.[Main link] = Sheet1_1.[Main link]
AND Sheet1.[Main project] = Sheet1_1.[Main project])

WHERE Sheet1_1.[Name] ='0.4 Rollout plan approved'
AND Sheet1_1.[%compl#] = 100
AND (Sheet1_1.[Task class] <> '***Sammelvorgang' AND Sheet1_1.[Task class] <> '' AND  Sheet1_1.[Task class] <> 'M D-Muster')

AND Sheet1.[Main project] = 'AUDI AG, Ingolstadt'
AND (Sheet1.[Task class] <> '***Sammelvorgang' AND Sheet1.[Task class] <> '' AND  Sheet1.[Task class] <> 'M D-Muster')
AND (Sheet1.[Name] NOT LIKE '0.*' AND Sheet1.[Name] NOT LIKE '1.*')
AND Sheet1.[Start] < DateAdd("d",-7,Now())

Answer 1

SELECT Sheet1.[Main project], Count(Sheet1.[Name]) AS Total
    FROM Sheet1
    GROUP BY Sheet1.[Main project]

像Count() 这样的聚合函数只有在您想要对表中所有内容进行总计数时才会自动工作。如果你想把它分解成更具体的分组，你需要一个GROUP BY 语句来告诉数据库如何分解它。

将它集成到更大的查询中应该不是问题：只需注意GROUP BY 子句位于WHERE 子句之后；因此你应该在最后添加它。