Question

在我的表格中，我有以下三个表格：

团队：

Id GUID UNIQUE PRIMARY
Name NVARCHAR

参与者：

Id GUID UNIQUE PRIMARY
FirstName NVARCHAR
[....]
TeamId GUID

ParticipantData：

Id GUID UNIQUE PRIMARY
Weight FLOAT
Date DATETIME
ParticipantId GUID
TeamId GUID

我需要的是一个SQL查询，该查询提供了Teams AND的所有列：

团队中参与者（TeamId）的ParticipantData中的第一个（按日期排序）条目的总和
团队中参与者（TeamId）的ParticipantData中最后（按日期排序）条目的总和

说明：

我有很多参与者（团队成员）以一定的时间间隔（体重+日期）报告体重。我要完成的工作是计算所有团队成员的体重减轻。

在2019-01-03参与者1报告了体重78

在2019-01-06参与者1报告了体重75

在2019-01-04上，参与者2报告了体重86

在2019-01-07上，参与者2报告了体重83

我需要查询以获取SumOfFirstWeights（78 + 86）= 164

我需要查询以获取SumOfLastWeights（75 + 83）= 158

这使我的体重减轻了6。

我尝试了以下多种组合：

Select *, 
(SELECT TOP (1) Sum(Weight) 
 FROM ParticipantData WHERE (TeamId = Teams.Id) 
 GROUP BY ParticipantId
)
ORDER BY Date As SumOfFirstWeights 
From Teams

Answer 1

您的问题是每个组中最大/最小的问题，此外，您需要这些值的总和。

select t.id, t.name, sum(t1.weight), sum(t2.weight)
from teams t
left join
(
    select pd.teamid, pd.participantid, pd.weight
    from ParticipantData pd
    join 
    (
        select teamid, participantid, min(date) min_date
        from ParticipantData 
        group by teamid, participantid
    ) t on pd.teamid = t.teamid and 
           pd.participantid = t.participantid and
           pd.date = t.min_date
) t1 on t.id = t1.teamid
left join 
(
    select pd.teamid, pd.participantid, pd.weight
    from ParticipantData pd
    join 
    (
        select teamid, participantid, max(date) max_date
        from ParticipantData 
        group by teamid, participantid
    ) t on pd.teamid = t.teamid and 
           pd.participantid = t.participantid and
           pd.date = t.max_date
) t2 on t1.teamid = t2.teamid and
        t1.participantid = t2.participantid
group by t.id, t.name

Answer 2

您要查找每个团队的第一行和最后一行。您可以为此使用分析功能。我正在使用ROW_NUMBER，即使参与者在同一天有两个条目，它也只能给我一个记录。

with pd as
(
  select
    participantid,
    weight,
    row_number() over (partition by participantid order by date) as one_is_first,
    row_number() over (partition by participantid order by date desc) as one_is_last
  from participantdata
)
, team_weights as
(
  select
    p.teamid,
    sum(case when pd.one_is_first = 1 then weight end) as first_weight,
    sum(case when pd.one_is_last = 1 then weight end) as last_weight,
    sum(case when pd.one_is_last = 1 then weight end) -
    sum(case when pd.one_is_first = 1 then weight end) as difference
  from pd
  join participant p on p.id = pd.participantid
  where (pd.one_is_first = 1 or pd.one_is_last = 1)
  group by p.teamid
)
select *
from teams
join team_weights on where team_weights.team_id = teams.id
order by teams.id;

选择相关表中第一行和最后一行的总和

2 个答案: