Question

我试图获得以下条件：每个LID与多个BID相关联，并且每个BID具有AvgTrustValue。我希望找到每个LID具有最低AvgTrustValue的BID

我做了以下事情：

SELECT DISTINCT LID, T1.BID, AvgTrustValue
FROM Loans T1, Repayments T2, 
    (SELECT BID, AVG(trust_value) As AvgTrustValue
    FROM Assign
    GROUP BY BID) T3
WHERE T1.LoanID = T2.LoanID
AND T1.BID = T3.BID
ORDER BY LID

但它只给我以下内容：

|   LID    |    BID    |
|S2262450A | S7444319C | 82
|S2848191X | S7611209X | 76
|S2848191X | S9981233W | 100
|S4495282I | S7444319C | 82
|S4792394D | S7444319C | 82
|S4792394D | S7611209X | 76
|S7145303Q | S7611209X | 76
|S7173102K | S7444319C | 82

我希望得到以下内容：

|   LID    |    BID    |
|S2262450A | S7444319C | 82
|S2848191X | S7611209X | 76
|S4495282I | S7444319C | 82
|S4792394D | S7611209X | 76
|S7145303Q | S7611209X | 76
|S7173102K | S7444319C | 82

我也试过以下但失败了：

SELECT DISTINCT LID, T1.BID, min(AvgTrustValue)
FROM Loans T1, Repayments T2, 
    (SELECT BID, AVG(trust_value) As AvgTrustValue
    FROM Assign
    GROUP BY BID) T3
WHERE T1.LoanID = T2.LoanID
AND T1.BID = T3.BID
GROUP BY LID
ORDER BY LID

非常感谢你。

Answer 1

您可以使用窗口函数row_number为每个盖子获取一行，且AvgTrustValue最少：

select *
from (
    select t.*, row_number() over (
            partition by lid order by AvgTrustValue
            ) as rn
    from your_table t
    ) t
where rn = 1;

或使用TOP with ties：

select top 1 with ties *
from your_table
order by row_number() over (
        partition by lid order by AvgTrustValue
        );

Answer 2

我认为'不存在'也没关系

从your_table a中选择lid，bid，avgvalue 哪里不存在（从your_table中选择1，其中lid = a.lid和avgvalue＆gt; a.avgvalue）

得到相关的最小值

2 个答案: