如何获取第一条和最后一条记录？一步解决？

Question

我有以下数据table。

 Record  Date        Price 
 A       3/1/2015    5 
 A       3/2/2015    6 
 A       3/3/2015    7 
 A       3/4/2015    10 
 B       2/1/2015    4 
 B       2/2/2015    6 
 B       2/3/2015    15 
 B       2/4/2015    2

如何输出一个 table 只显示 table 中第一个日期和 table 中最后一个日期的每条记录的第一个价格和最后一个价格.输出列将是记录、第一价格、最后价格。我正在寻找一种易于实施的一步解决方案，以便创建自定义视图。

所需的输出为：

 Record     FirstPrice   LastPrice
 A          5            10 
 B          4            2

Answer 1

"in order to create a custom view."...您希望在 Oracle/MySql 中将此操作作为 CREATE VIEW 还是只是 query/select 语句？

Answer 2

也许您正在寻找这样的东西？

select R.Record, FD.Price as MinPrice, LD.Price as MaxPrice
from Records R
join (
    select Price, R1.Record
    from Records R1
    where Date = (select MIN(DATE) from Records R2 where R2.Record = R1.Record)
  ) FD on FD.Record = R.Record
join (
   select Price, R1.Record
    from Records R1
    where Date = (select MAX(DATE) from Records R2 where R2.Record =     R1.Record)
  ) LD on LD.Record = R.Record
group by R.Record

http://sqlfiddle.com/#!9/d047b/26

Answer 3

获取按记录字段分组的最小和最大聚合日期并连接回根数据。如果同一日期的同一记录字段可以有多个记录，则必须使用 min、max 或 avg 来获取该日期的一个值。

SQLFiddle: http://sqlfiddle.com/#!9/1158b/3

SELECT anchorData.Record
,      firstRecord.Price
,      lastRecord.Price
FROM (
    SELECT Record
    ,      MIN(Date) AS FirstDate
    ,      MAX(Date) AS LastDate
    FROM   Table1
    GROUP BY Record
    ) AS anchorData
JOIN   Table1 AS firstRecord
ON     firstRecord.Record = anchorData.Record
AND    firstRecord.Date = anchorData.FirstDate
JOIN   Table1 AS lastRecord
ON     lastRecord.Record = anchorData.Record
AND    lastRecord.Date = anchorData.LastDate

如何获取第一条和最后一条记录？一步解决？

How to Obtain First and Last record ? One Step Solution?

mysql

sql

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