SQL display MIN（）列，并显示其他列

我正在编写一份报告，其中需要显示学生id、分数和分数提交的最低日期/时间。该表将包含每个学生在多天内的多个分数

我遇到的问题（使用下面的示例代码）是，我会为每个分数获得一个新行，而不是每个学生只显示一行学生id、分数和日期

示例源表列 学生证| 得分| 记分日

select tests.student_id
      ,tests.score
      ,min(score_date)
from tests

group by tests.student_id
        ,tests.score

您可以使用

行编号（）

进行此操作

select * from (
    select t1.student_id
          ,t1.score
          ,row_number() over (partition by t1.student_id order by t1.score_date) rn 
          ,t1.score_date
    from tests t1) t
where t.rn = 1

使用

相关子查询

还有一个技巧

select student_id
    , min(score_date) score_date
    , (select top 1 score from tests where score_date = min(t.score_date) and student_id = t.student_id) as score
from tests t
group by student_id

或者，如果您正在使用sql server 2012及更高版本。您可以最大限度地使用

first\u value（）

函数

select distinct first_value(student_id) over (partition by student_id order by score_date)
    , first_value(score_date) over (partition by student_id order by score_date)
    , first_value(score) over (partition by student_id order by score_date)
from tests t
group by student_id

试试这个

SELECT student_id, score, score_date
FROM tests T 
INNER JOIN (SELECT student_id, Min(score_date) AS score_date FROM tests) X 
ON T.student_id = X.student_id AND T.score_date = X.score_date

---

如果你想知道每个学生得分最低时的所有日期

然后，我想到了窗口函数。按升序

得分排序

WITH CTE_STUDENT_SCORES AS
(
  SELECT student_id, score, score_date
  , DENSE_RANK() OVER (PARTITION BY student_id ORDER BY score ASC) AS StudentAscendingScoreRank
  FROM tests
)
SELECT student_id, score, score_date
FROM CTE_STUDENT_SCORES
WHERE StudentAscendingScoreRank = 1
ORDER BY student_id, score_date

如果只需要学生最低分数的最新分数日？
然后可以限制行数。
按升序得分和降序得分日期排序

WITH CTE_STUDENT_SCORES AS
(
  SELECT student_id, score, score_date
  , ROW_NUMBER() OVER (PARTITION BY student_id ORDER BY score ASC, score_date DESC) AS StudentAscendingScoreRownum
  FROM tests
)
SELECT student_id, score, score_date
FROM CTE_STUDENT_SCORES
WHERE StudentAscendingScoreRownum = 1
ORDER BY score_date DESC, student_id;

---

使用

row\u number（）

窗口函数获取最早日期您希望在学生ID/最低日期旁边看到的分数是多少？