sql-server – 计算与第三个表关联的两个表的行

2019年7月28日 188次阅读

我有三个表：数据,网络和软件.数据表具有我的所有客户端名称,而网络和软件表具有服务票证.我们需要每个客户每月至少从一个表(网络或软件)中选择一张票.我需要一个查询来计算每个月数据表中每个客户的表(网络和软件)的票证.

my tables

欲望结果：
Final query

我找到了使用此查询计数的方法,但我不知道如何从两个表计数.

SELECT institucion
    ,(SELECT count(institucion) FROM network WHERE data.institucion = network.institucion and fecha like '2016-07%')as July
    ,(SELECT count(institucion) FROM network WHERE data.institucion = network.institucion and fecha like '2016-08%')as August
    ,(SELECT count(institucion) FROM network WHERE data.institucion = network.institucion and fecha like '2016-09%')as September
    ,(SELECT count(institucion) FROM network WHERE data.institucion = network.institucion and fecha like '2016-10%')as October
    ,(SELECT count(institucion) FROM network WHERE data.institucion = network.institucion and fecha like '2016-11%')as November
    ,(SELECT count(institucion) FROM network WHERE data.institucion = network.institucion and fecha like '2016-12%')as December
    ,(SELECT count(institucion) FROM network WHERE data.institucion = network.institucion and fecha like '2017-01%')as January
    ,(SELECT count(institucion) FROM network WHERE data.institucion = network.institucion and fecha like '2017-02%')as February
    ,(SELECT count(institucion) FROM network WHERE data.institucion = network.institucion and fecha like '2017-03%')as March
    ,(SELECT count(institucion) FROM network WHERE data.institucion = network.institucion and fecha like '2017-04%')as April
    ,(SELECT count(institucion) FROM network WHERE data.institucion = network.institucion and fecha like '2017-05%')as May
    ,(SELECT count(institucion) FROM network WHERE data.institucion = network.institucion and fecha like '2017-06%')as June
FROM data
where data.erate = 'y'
order by institucion

最佳答案 我认为您需要联合网络和软件表,然后使用条件聚合来获取每个感兴趣的月份的计数摘要.

SELECT t1.institucion,
       SUM(CASE WHEN t1.fetcha LIKE '2016-07%' THEN 1 ELSE 0 END) AS July,
       SUM(CASE WHEN t1.fetcha LIKE '2016-08%' THEN 1 ELSE 0 END) AS August,
       SUM(CASE WHEN t1.fetcha LIKE '2016-09%' THEN 1 ELSE 0 END) AS September,
       SUM(CASE WHEN t1.fetcha LIKE '2016-10%' THEN 1 ELSE 0 END) AS October,
       SUM(CASE WHEN t1.fetcha LIKE '2016-11%' THEN 1 ELSE 0 END) AS November,
       SUM(CASE WHEN t1.fetcha LIKE '2016-12%' THEN 1 ELSE 0 END) AS December,
       SUM(CASE WHEN t1.fetcha LIKE '2017-01%' THEN 1 ELSE 0 END) AS January,
       SUM(CASE WHEN t1.fetcha LIKE '2017-02%' THEN 1 ELSE 0 END) AS February,
       SUM(CASE WHEN t1.fetcha LIKE '2017-03%' THEN 1 ELSE 0 END) AS March,
       SUM(CASE WHEN t1.fetcha LIKE '2017-04%' THEN 1 ELSE 0 END) AS April,
       SUM(CASE WHEN t1.fetcha LIKE '2017-05%' THEN 1 ELSE 0 END) AS May,
       SUM(CASE WHEN t1.fetcha LIKE '2017-06%' THEN 1 ELSE 0 END) AS June
FROM
(
    SELECT institucion, fecha, service
    FROM network n
    UNION ALL
    SELECT institucion, fecha, service
    FROM software s
) t1
INNER JOIN data t2
    ON t1.institucion = t2.institucion
WHERE t2.erate = 'y'
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