SQL嵌套选择和别名

形势

我有一个典型的MS Access数据库，其中包含有关公司、薪酬、员工和职位的信息。部分表格包括：

tbl_报告（报告ID主键，报告年度）

tbl_员工（员工ID主键）

tbl_Pay（工资ID主键、工资、员工ID FK、报告ID FK）

tbl_职位（职位ID主键、职位、员工ID FK、报告ID FK）

我有一个查询，用于选择每个职位和年份的薪资，以生成：

qry_Salary_by_Position_Year:   (This query is parameterised to accept a 'Year').

Year | Salary | Position
------------------------
2014 |  100   |   CEO
2013 |  200   |   CEO
2014 |  300   |   CFO
2014 |  200   |  Chairman
2013 |  150   |   CEO

etc.

然后，我使用另一个查询来提取给定职位的最高x%工资：

qry_Select_Top_25:

SELECT TOP 25 PERCENT Salary, Year, Position
FROM qry_Salary_by_Position_Year;

它给出了类似于：

Salary | Year | Position
------------------------
 100   | 2014 |  CEO
 100   | 2014 |  CFO
 200   | 2014 |  CFO

问题

我想要的是一个显示最大值（25%）、最大值（50%）、最大值（75%）、最大值（X%）的最终表格，按位置和年份分组，例如：

Year | Position | 25th | 50th | 75th 
-------------------------------------
2013 |   CEO    |  10  |  30  |  75  
2014 |   CEO    |  20  |  50  |  80  
2014 |   CFO    |  15  |  30  |  90
2014 | Chairman |  20  |  25  |  30

我可以使用

SELECT Year, Position, Max(qry50.Salary) AS 50_Percentile
FROM (SELECT TOP 50 PERCENT qry_Salary_by_Position_Year.Salary, Year, Position 
FROM qry_Salary_by_Position_Year)  AS qry50
WHERE Position IN  (SELECT DISTINCT Position FROM qry_Salary_by_Position_Year) AND Year IN (SELECT DISTINCT Year FROM qry_Salary_by_Position_Year)
GROUP BY Year, Position;

但我无法理解如何使用正确的别名等构造查询，以便将其他百分比值作为其他列添加进来。有人有任何建议/意见/问题吗

编辑

我可能已经想出了一个解决方案，我现在正在检查：

SELECT qry.Year, qry.Position, Max(qry25.Salary) AS 25_Percentile, Max(qry50.Salary) AS 50_Percentile, Max(qry75.Salary) AS 75_Percentile, Max(qry100.Salary) AS 100_Percentile
FROM 
((((qry_Salary_by_Position_Year qry
LEFT OUTER JOIN (SELECT TOP 50 PERCENT  Salary, Year, Position FROM qry_Salary_by_Position_Year) AS qry50 ON qry.Year = qry50.Year AND qry.Position = qry50.Position)
LEFT OUTER JOIN (SELECT TOP 25 PERCENT Salary, Year, Position FROM qry_Salary_by_Position_Year) AS qry25 ON qry.Year = qry25.Year AND qry.Position = qry25.Position)
LEFT OUTER JOIN (SELECT TOP 75 PERCENT Salary, Year, Position FROM qry_Salary_by_Position_Year) AS qry75 ON qry.Year = qry75.Year AND qry.Position = qry75.Position)
LEFT OUTER JOIN (SELECT TOP 100 PERCENT Salary, Year, Position FROM qry_Salary_by_Position_Year) AS qry100 ON qry.Year = qry100.Year AND qry.Position = qry100.Position)
GROUP BY qry.Year, qry.Position

---

我想这就是我想要的：

SELECT qry.Year, qry.Position, Max(qry25.Salary) AS 25_Percentile, Max(qry50.Salary) AS 50_Percentile, Max(qry75.Salary) AS 75_Percentile, Max(qry100.Salary) AS 100_Percentile
FROM 
((((qry_Salary_by_Position_Year qry
LEFT OUTER JOIN (SELECT TOP 50 PERCENT  Salary, Year, Position FROM qry_Salary_by_Position_Year) AS qry50 ON qry.Year = qry50.Year AND qry.Position = qry50.Position)
LEFT OUTER JOIN (SELECT TOP 25 PERCENT Salary, Year, Position FROM qry_Salary_by_Position_Year) AS qry25 ON qry.Year = qry25.Year AND qry.Position = qry25.Position)
LEFT OUTER JOIN (SELECT TOP 75 PERCENT Salary, Year, Position FROM qry_Salary_by_Position_Year) AS qry75 ON qry.Year = qry75.Year AND qry.Position = qry75.Position)
LEFT OUTER JOIN (SELECT TOP 100 PERCENT Salary, Year, Position FROM qry_Salary_by_Position_Year) AS qry100 ON qry.Year = qry100.Year AND qry.Position = qry100.Position)
GROUP BY qry.Year, qry.Position

我在另一篇帖子中的回答引出了这个解决方案：