本文介紹了不使用子查詢的高級分組的處理方法,對大家解決問題具有一定的參考價值,需要的朋友們下面隨著小編來一起學習吧!
問題描述
這是我擁有的數據樣本.
This is a sample of the data that I have.
-ID- -Rank- -Type- -Status- -Amount-
1142474 2 Under Offer Approved 23
1148492 1 Present Current 56
1148492 2 Under Offer Approved 3
2273605 1 Present Current 24
ID 相同的地方我只想要排名最高的記錄.所以查詢的最終結果.
Where the ID is the same I only want the record with the highest rank. So the end result of the query.
-ID- -Rank- -Type- -Status- -Amount-
1142474 2 Under Offer Approved 23
1148492 1 Present Current 56
2273605 1 Present Current 24
現在獲取原始數據集是一個昂貴的操作,所以我不想想要做一個按 ID 分組和然后分鐘排名,然后然后重新連接到數據集上.因此,查詢需要以另一種方式工作.
Now to get the original data set is an expensive operation, so I don't want to do a group by the ID and then mins the rank and then joins back onto the dataset again. Hence the query needs to do its work another way.
干杯安東尼
推薦答案
select t1.id
, t1.rank
, t1.type
, t1.status
, t1.amount
from my_table t1
left outer join my_table as t2
on t1.id = t2.id
and
t2.rank < t1.rank
where t2.id is null
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