我有一个表，其中列B、C和D可以被视为标识符，列E-I是值。根据标识符，将存在一些非唯一的行，即B、C和D的值与其他行的值匹配（可能不止一行匹配）。
我想要一个返回所有行的查询，除了那些非唯一的行。在这些情况下，我希望只返回一行，并对其值求和，只有一个例外，即列E。这应该是相对于列F的加权平均值，即对于每个匹配行，返回的值应该是E*F/F的和
例如
E, F
7, 1
9, 4
E = (7*1 + 9*4)/(1+4) = 8.6
我可以使用什么查询来返回所需的结果集？
非常感谢所有的帮助！
我认为应该这样做：
select B, C, D, sum(E*F) / sum(F), sum(F), sum(G), sum(H), sum(I)
from MyTable
group by B, C, D
SELECT B, C, D,
SUM(E * F) / SUM(F) AS E_WEIGHTED,
SUM(F) AS F_SUM,
SUM(G) AS G_SUM,
SUM(H) AS H_SUM,
SUM(I) AS I_SUM
FROM TableX
GROUP BY B, C, D
通常，GROUP BY子句将合并共享重复值的行（在GROUP BY子句中命名的列）。
SELECT B,C,D,SUM(E*F)/SUM(F), SUM(F), SUM(G), SUM(H), SUM(I)
FROM my_table
GROUP BY B,C,D;
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