在clickhouse中与max（）聚合时如何连续选择相应的值？

Posted 2023-03-25

【中文标题】在clickhouse中与max（）聚合时如何连续选择相应的值？

【英文标题】：How to select corresponding value in a row when aggregating with max() in clickhouse?

【发布时间】：2021-09-30 12:49:36

【问题描述】：

我在数据库中有一个这样的表：

这是一个UserID的一部分，但实际上有很多。

create table MY_TABLE
(
    UserID Nullable(String),
    OID int,
    TotalHits Nullable(int),
    DaysOfHits Nullable(int),
    UniqPrimaryEvents Nullable(int)
)
engine = Memory;

insert into MY_TABLE (UserID, OID, TotalHits, DaysOfHits, UniqPrimaryEvents) values ('1000c666-04db-4447-9ea1-ecf1e2275c81', 6564023, 4, 1, 0);
insert into MY_TABLE (UserID, OID, TotalHits, DaysOfHits, UniqPrimaryEvents) values ('1000c666-04db-4447-9ea1-ecf1e2275c81', 6546504, 9, 1, 0);
insert into MY_TABLE (UserID, OID, TotalHits, DaysOfHits, UniqPrimaryEvents) values ('1000c666-04db-4447-9ea1-ecf1e2275c81', 6538286, 12, 2, 0);
insert into MY_TABLE (UserID, OID, TotalHits, DaysOfHits, UniqPrimaryEvents) values ('1000c666-04db-4447-9ea1-ecf1e2275c81', 6536273, 8, 2, 0);
insert into MY_TABLE (UserID, OID, TotalHits, DaysOfHits, UniqPrimaryEvents) values ('1000c666-04db-4447-9ea1-ecf1e2275c81', 6534195, 57, 6, 0);
insert into MY_TABLE (UserID, OID, TotalHits, DaysOfHits, UniqPrimaryEvents) values ('1000c666-04db-4447-9ea1-ecf1e2275c81', 6528643, 4, 1, 0);
insert into MY_TABLE (UserID, OID, TotalHits, DaysOfHits, UniqPrimaryEvents) values ('1000c666-04db-4447-9ea1-ecf1e2275c81', 6496311, 7, 2, 0);
insert into MY_TABLE (UserID, OID, TotalHits, DaysOfHits, UniqPrimaryEvents) values ('1000c666-04db-4447-9ea1-ecf1e2275c81', 6492524, 7, 1, 0);
insert into MY_TABLE (UserID, OID, TotalHits, DaysOfHits, UniqPrimaryEvents) values ('1000c666-04db-4447-9ea1-ecf1e2275c81', 6475804, 9, 1, 0);
insert into MY_TABLE (UserID, OID, TotalHits, DaysOfHits, UniqPrimaryEvents) values ('1000c666-04db-4447-9ea1-ecf1e2275c81', 6424164, 5, 1, 0);
insert into MY_TABLE (UserID, OID, TotalHits, DaysOfHits, UniqPrimaryEvents) values ('1000c666-04db-4447-9ea1-ecf1e2275c81', 6403817, 8, 1, 0);
insert into MY_TABLE (UserID, OID, TotalHits, DaysOfHits, UniqPrimaryEvents) values ('1000c666-04db-4447-9ea1-ecf1e2275c81', 6403592, 9, 1, 0);
insert into MY_TABLE (UserID, OID, TotalHits, DaysOfHits, UniqPrimaryEvents) values ('1000c666-04db-4447-9ea1-ecf1e2275c81', 6400394, 13, 1, 0);
insert into MY_TABLE (UserID, OID, TotalHits, DaysOfHits, UniqPrimaryEvents) values ('1000c666-04db-4447-9ea1-ecf1e2275c81', 6383627, 8, 1, 0);
insert into MY_TABLE (UserID, OID, TotalHits, DaysOfHits, UniqPrimaryEvents) values ('1000c666-04db-4447-9ea1-ecf1e2275c81', 6364163, 4, 1, 0);
insert into MY_TABLE (UserID, OID, TotalHits, DaysOfHits, UniqPrimaryEvents) values ('1000c666-04db-4447-9ea1-ecf1e2275c81', 6349018, 7, 1, 0);
insert into MY_TABLE (UserID, OID, TotalHits, DaysOfHits, UniqPrimaryEvents) values ('1000c666-04db-4447-9ea1-ecf1e2275c81', 6270551, 6, 1, 0);

我需要聚合表格，并在结果中包含 agg funcs 的结果和来自 OID 的相应值：

我正在做类似的事情：

SELECT
    UserID,
    uniq(OID) AS UniqObjects,
    sum(TotalHits) AS TotalHits,
    round(avg(DaysOfHits), 2) AS AvgObjectHitDays,
    max(DaysOfHits) AS MaxHitPeriod,
-- here I need OID corresponding to max(DaysOfHits) value
    round((avg(DaysOfHits) / max(DaysOfHits)) * 100, 2) AS PerOfMaxHit

我试过像anyIf(OID, DaysOfHits = max(DaysOfHits)), 这样的东西，但你不能在 agg func 里面有 agg func。

PS Select 的来源是另一个joined select，而不是单个表。

请帮忙！

【问题讨论】：

你能告诉我们你希望你的输出在 desc 中的样子吗？

【参考方案1】：

argMax 是个好东西！我只是一个初学者，对不起）

答案是 argMax(OID, DaysOfHits) - 它会根据要求返回最大 DaysOfHits 的 OID

【讨论】：

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