我需要在Access中加入3个表。所以我创建了查询以获得＆＃34; Team＆＃34;具有内连接的字段[表A]到[表C] on＆＃34; Assoc。 NO＆＃34;然后另一个[表B]到[表C]也在＆＃34; Assoc。 NO]。
我的问题
我使用基于[表C]和[表A]的查询来获得月份，但是如果它们在[表A]中不存在并且仅存在[表B]则我错过了几个月。我是否需要创建一个只有几个月和几年的表并创建一个连接？我为长篇文章道歉，但希望提供尽可能多的信息。在此先感谢您的帮助。
Table A
|Name | Assoc. NO |month|Year|Product|SaleA|
|John Smith | 1 |Jan |2016|Apple |$10 |
|John Smith | 1 |Jan |2016|Pear |$5 |
|John Smith | 1 |Feb |2016|Apple |$10 |
|George Martin| 2 |Feb |2016|Apple |$10 |
|George Martin| 2 |Feb |2016|Apple |$10 |
|George Martin| 2 |Feb |2016|Pear |$5 |
Table B
|Name | Assoc. NO |month|Year|Service |SaleB|
|John Smith | 1 |Jan |2016|oil change|$25 |
|George Martin| 2 |Jan |2016|oil change|$25 |
|Mark James | 3 |Feb |2016|oil change|$25 |
|Mark James | 3 |Mar |2016|oil change|$25 |
|George Martin| 2 |Mar |2016|oil change|$25 |
Table C
|Team |Name | Assoc. NO |
|Team A |John Smith | 1 |
|Team B |George Martin| 2 |
|Team B |Mark James | 3 |
我希望看到以下内容：
Query
|Team |Name | Month |Sale |SaleB|SUM(SaleA,SaleB)|
|-------|-------------|--------|-----|-----|----------------|
|Team A |John Smith | Jan | $15 | $25 | $40 |
|Team A |John Smith | Feb | $10 | $0 | $10 |
|Team B |George Martin| Jan | $0 | $25 | $25 |
|Team B |George Martin| Feb | $25 | $0 | $25 |
|Team B |George Martin| Mar | $0 | $25 | $25 |
|Team C |Mark James | Feb | $0 | $25 | $25 |
|Team C |Mark James | Feb | $0 | $25 | $25 |
答案 0 :(得分：0)
SELECT [Table C].Team, [Table C].Name, [Table C].[Assoc No], Month, Sum(T.SaleA) AS TotA, Sum(T.SaleB) AS TotB, [TotA]+[TotB] AS Total
FROM
(select [Assoc no], Month, SaleA, 0 as SaleB from [Table A]
UNION ALL select [Assoc No], Month, 0, Saleb from [Table B]) AS T
INNER JOIN [Table C] ON T.[Assoc No]= [Table C].[Assoc No]
GROUP BY [Table C].Team, [Table C].Name, Table C].[Assoc No], T.Month;