Question

我有一个类似于以下的表（使用sql-server 2012）：

primaryid     Caseid     Indication   Reaction        Drugname
1             2          Pain         Vomiting        DrugA
1             2          Pain         Vomiting        DrugB
3             4          Pain         Headache        DrugA
3             4          Pain         Headache        DrugB
16            17         Pain         Sleepiness      DrugC
16            17         Pain         Sleepiness      DrugD
16            18         Pain         Sleepiness      DrugC
16            18         Pain         Sleepiness      DrugD

请注意，primaryid和caseid不是唯一的密钥标识符，值或多或少是随机的，仅用于演示我的数据的性质。我有兴趣知道我是否可以查询此数据以获得如下结果？：

primaryid     Caseid     Indication   Reaction        Drugname        Count
1             2          Pain         Vomiting        DrugA, DrugB     2
3             4          Pain         Headache        DrugA, DrugB     2 
16            17         Pain         Sleepiness      DrugC, DrugD     2
16            18         Pain         Sleepiness      DrugC, DrugD     2

非常感谢任何帮助。上面的表是一百万个连接的结果:)最后我很难过。

Answer 1

declare @table table (primaryid int, caseid int, indication varchar(10), reaction varchar(10), drugname varchar(10))

insert into @table values (1,2 ,'Pain','Vomiting','DrugA')
insert into @table values (1, 2,'Pain','Vomiting','DrugB')
insert into @table values (3,4,'Pain','Headache','DrugA')
insert into @table values (3,4,'Pain','Headache','DrugB')
insert into @table values (16,17,'Pain','Sleepiness','DrugC')
insert into @table values (16,17,'Pain','Sleepiness','DrugD')
insert into @table values (16,18,'Pain','Sleepiness','DrugC')
insert into @table values (16,18,'Pain','Sleepiness','DrugD')

SELECT
    G.primaryid,
    G.caseid,
    G.indication,
    g.reaction,
    stuff(
    (
    select cast(',' as varchar(max)) + U.drugname
    from @table U
    WHERE U.primaryid = G.primaryid
    and u.caseid = g.caseid
    and u.indication = g.indication
    and u.reaction = g.reaction
    order by U.primaryid
    for xml path('')
    ), 1, 1, '') AS drugname,
    count(*) Count
FROM
    @table G
    group by G.primaryid,
    G.caseid,
    G.indication,
    g.reaction

查询以对同一列中的两行中的值进行分组并显示计数

1 个答案: