Sql Select语句，但仅返回另一个联接表的最新项

比如说，我选择了一位候选人，详细介绍了他们的工作经历

Select candidate.id, candidate.firstname +' '+ candidate.lastname as 'Candidate Name', cwh.dateworked
from candidate
inner join canworkhistory cwh on candidate.id = cwh.candidateid

现在有多条关于候选人工作日期的记录，但我只想要最近的一条

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如何对这些子项进行排序，以便在上述查询中返回前1名？

您可以尝试使用窗口函数-row_number（）

---

您可以将派生表与

分组依据

和

最大值

一起使用：

Select candidate.id, 
       candidate.firstname +' '+ candidate.lastname as 'Candidate Name', 
       cwh.dateworked
from candidate
inner join (
    select candidateid, max(dateworked) as dateworked
    from canworkhistory
    group by candidateid
) cwh on candidate.id = cwh.candidateid

---

您可以应用最新的行：

Select candidate.id, candidate.firstname +' '+ candidate.lastname as 'Candidate Name', cwh.dateworked
outer apply (select top 1 * from canworkhistory where candidate.id = canworkhistory.candidateid order by dateworked desc) cwh
from candidate

你可以试试下面的方法

 with cte as
   (
    Select candidate.id, candidate.firstname +' '+ candidate.lastname 
    as 'Candidate   Name', cwh.dateworked
    from candidate
    inner join canworkhistory cwh on candidate.id = cwh.candidateid
  ) select t.* from cte t where t.dateworked =
                ( select max(dateworked) from canworkhistory t1
                   where t1.candidateid=t.id
                     group by candidateid
                   )

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您也可以尝试使用CTE

;WITH RecentWork
     AS (SELECT
           candidateid
           ,max(dateworked)
         FROM
           canworkhistory
         GROUP  BY
          candidateid)
SELECT
  candidate.id
  ,candidate.firstname + ' ' + candidate.lastname AS 'Candidate Name'
  ,RecentWork.dateworked
FROM
  candidate
  INNER JOIN RecentWork
          ON candidate.id = RecentWork.candidateid 

---

No FROM子句？是否有原因不能按日期排序然后返回第一行？您的

FROM

位于

内部联接之后？这只是一个说明问题要点的示例…如果能看到所有答案之间的性能比较（因为它们似乎都提供了正确的结果），那将非常有趣…也许是从其他答案中找到的最好的极简主义方法！
;WITH RecentWork
     AS (SELECT
           candidateid
           ,max(dateworked)
         FROM
           canworkhistory
         GROUP  BY
          candidateid)
SELECT
  candidate.id
  ,candidate.firstname + ' ' + candidate.lastname AS 'Candidate Name'
  ,RecentWork.dateworked
FROM
  candidate
  INNER JOIN RecentWork
          ON candidate.id = RecentWork.candidateid