从多个子表返回的虚总数SUM总计

TABLE1 - RegId (int) pk, RegDate (date), CityId, Tons1(int), Tons2(int) 

TABLE2 - RegId(int) fk, OtherDate (date) 

TABLE3 - id, City 

    SELECT c.City 
     , SUM(t1.Tons1 + t1.Tons2) as 'TotalTons' 

    FROM Table1 t1 
    JOIN Table2 t2 ON t1.RegId = t2.RegId 
    JOIN table3 c ON t1.CityId = c.Id 
    WHERE YEAR(t2.OtherDate) = '2016' 
    GROUP BY c.City

如果表2中存在多个匹配项，则'TotalTons'将被重复。如果我删除了连接，那就没关系，但我必须为WHERE子句创建table2日期。从多个子表返回的虚总数SUM总计

样品：

TABLE1 
(20, '2016-2-2', 3, 2, 3) 
(21, '2016-4-12', 7, 3, 5) 
(22, '2016-4-12', 7, 6, 3) 


TABLE 2 
(20, '2016-2-2') 
(20, '2016-2-3') 
(20, '2016-2-5') 
(20, '2016-2-1') 
(21, '2016-5-12') 
(22, '2016-9-2') 


TABLE 3 
(3, 'Dallas') 
(7, 'Kansas')

成绩

City TotalTons 
---- --------- 
Dallas 20 (should be 5) 
Kansas 17 (Correct)

所以达拉斯总吨为5，但因为有表2中5个不同的行为的RegID 20，它乘以4倍。

如何让它停止乘以t2结果的SUM？

来源

2017-04-04 BattlFrog

你可以替换加入与存在和子查询：

SELECT c.City 
, SUM(t1.Tons1 + t1.Tons2) as 'TotalTons' 
FROM Table1 t1 
JOIN table3 c ON t1.CityId = c.Id 
WHERE EXISTS (
    SELECT 1 
    FROM Table2 t2 
    WHERE t2.RegId = t1.RegId 
    AND YEAR(t2.OtherDate) = '2016' 
) 
GROUP BY c.City

来源

2017-04-04 19:08:49

这工作，谢谢。因此，这是否是因为不是返回匹配的行而只是在匹配时从子查询中返回1？ – BattlFrog

差不多。如果任何行或条状图符合条件，则存在返回true。 –

试试这个：

DECLARE @TABLE1 TABLE(RegId INT,RegDate DATE, CityId INT, Tons1 INT, Tons2 INT) 
INSERT INTO @TABLE1 VALUES 
(20, '2016-2-2', 3, 2, 3),(21, '2016-4-12', 7, 3, 5),(22, '2016-4-12', 7, 6, 3) 

DECLARE @TABLE2 TABLE(RegId INT,OtherDate DATE) 
INSERT INTO @TABLE2 VALUES (20, '2016-2-2'),(20, '2016-2-3'),(20, '2016-2-5'), 
(20, '2016-2-1'),(21, '2016-5-12'),(22, '2016-9-2') 

DECLARE @TABLE3 TABLE(id INT,City NVARCHAR(10)) 
INSERT INTO @TABLE3 VALUES (3, 'Dallas'),(7, 'Kansas') 

SELECT DISTINCT B.City,B.TotalTons FROM (SELECT T2.*,CityId FROM @TABLE2 T2 
LEFT JOIN @TABLE1 T1 ON T1.RegId = T2.RegId) A LEFT JOIN (SELECT CityId,City, SUM(Tons1+Tons2) TotalTons 
FROM @TABLE3 T3 LEFT JOIN @TABLE1 T1 ON T1.CityId = T3.id GROUP BY CityId,City) B ON A.CityId = B.CityId 
WHERE YEAR(OtherDate) = '2016' -- change your date clause

希望它能帮助。 :)

来源

2017-04-04 19:40:19

从多个子表返回的虚总数SUM总计

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