在sql中对行进行分组

Question

如下所示，如果campaignIds相等，我想让它们成为组。但我无法弄清楚如何做到这一点。 CampaignId分组无效。

实例：http://www.sqlfiddle.com/#!3/cb1dd/2

Answer 1

它应该得到每个费率数的评级总和吗？您可以在CampaignID和Group By函数上使用SUM()来完成此操作。

select CampaignId,
    sum(case when RateNumber = 1 then RateValue else null end) as Rate1,
    sum(case when RateNumber = 2 then RateValue else null end) as Rate2,
    sum(case when RateNumber = 3 then RateValue else null end) as Rate3,
    sum(case when RateNumber = 4 then RateValue else null end) as Rate4,
    sum(case when RateNumber = 5 then RateValue else null end) as Rate5,
    sum(case when RateNumber = 6 then RateValue else null end) as Rate6,
    sum(case when RateNumber = 7 then RateValue else null end) as Rate7,
    sum(case when RateNumber = 8 then RateValue else null end) as Rate8,
    sum(case when RateNumber = 9 then RateValue else null end) as Rate9,
    sum(case when RateNumber = 10 then RateValue else null end) as Rate10,
    sum(case when RateNumber = 11 then RateValue else null end) as Rate11,
    sum(case when RateNumber = 12 then RateValue else null end) as Rate12,
    sum(case when RateNumber = 13 then RateValue else null end) as Rate13,
    sum(case when RateNumber = 14 then RateValue else null end) as Rate14,
    sum(case when RateNumber = 15 then RateValue else null end) as Rate15,
    sum(case when RateNumber = 16 then RateValue else null end) as Rate16,
    sum(case when RateNumber = 17 then RateValue else null end) as Rate17,
    sum(case when RateNumber = 18 then RateValue else null end) as Rate18,
    sum(case when RateNumber = 19 then RateValue else null end) as Rate19,
    sum(case when RateNumber = 20 then RateValue else null end) as Rate20,
    sum(case when RateNumber = 21 then RateValue else null end) as Rate21,
    sum(case when RateNumber = 22 then RateValue else null end) as Rate22,
    sum(case when RateNumber = 23 then RateValue else null end) as Rate23,
    sum(case when RateNumber = 24 then RateValue else null end) as Rate24
    from CampaignRate
group by CampaignId;

查看fiddle。

Answer 2

使用SQL Server中的 pivot 功能，可能会产生更易读的SQL http://msdn.microsoft.com/en-gb/library/ms177410(v=sql.105).aspx

SELECT CampaignId, [1] AS Rate1, [2] AS Rate2, [3] AS Rate3
FROM 
(SELECT CampaignId, RateNumber, RateValue
FROM CampaignRate) p
PIVOT
(
SUM (RateValue)
FOR RateNumber IN
( [1], [2], [3] )
) AS pvt
ORDER BY pvt.CampaignId;
    GO