如何查找最低值和相应的日期SQL-Server 2014

Question

我有样本数据See the SQL Fiddle。我想查找值列中的最低值和上传日期列中的最低值的日期。我尝试了下面的查询，它没有正常工作并显示所有值。

SELECT 
    username, 
    MIN(Value1) AS MinValue1, 
    CASE 
     WHEN value1 = MIN(value1) THEN uploaded_date 
    END 
    AS MinDate 
FROM 
    test 

GROUP BY 
    username 

Answer 1

您可以使用RANK窗函数查找每个用户名的最小值：

SELECT username, value1, uploaded_date 
FROM (SELECT username, value1, uploaded_date, 
       RANK() OVER (PARTITION BY username ORDER BY value1 ASC) AS rk 
     FROM test) t 
WHERE rk = 1 

SQLFIddle

Answer 2

我希望这将帮助你

;with CTE as(
    SELECT username, 
     MIN(Value1) AS MinValue1 
    FROM 
     test 
    GROUP BY 
    username 
) 

    select c.username,MinValue1,dt.uploaded_date from CTE c 
    cross apply(select top 1 uploaded_date from test where value1=c.MinValue1 and username=c.username order by uploaded_date desc) dt 

Answer 3

SELECT test. username,value1,MIN(uploaded_date )FROM 
(Select MIN(value1) MinValue1,username from test group by username) A 
INNER JOIN 
test 
ON A.MinValue1 = test.Value1 
AND A.username = test.username 
GROUP BY 
test. username,value1 

，因为你正在使用的列在选择列表中，以便在GROUP BY子句意志集团所有不同值到每一行

Answer 4

select Value1, update_date from test order by Value1 limit 1