如何将select语句与新的动态值合并为列？

Question

在我的SQL Server的代码，我有这样的select语句

select distinct 
    a.HireLastName, 
    a.HireFirstName, 
    a.HireID, 
    a.Position_ID, 
    a.BarNumber, 
    a.Archived, 
    a.DateArchived, 
    b.Position_Name 
from NewHire a 
join Position b on a.Position_ID = b.Position_ID 
join WorkPeriod c on a.hireID = c.HireID 
where a.Archived = 0 and c.InquiryID is not null 
order by a.HireID DESC, a.HireLastName, a.HireFirstName 

而且我想一个新列添加到它。然而，这个列不是表格中的一列，它只是用来存储我从现有列中计算得出的float。

我得到的数字是这样计算的： @acc是上述select语句中的a.HireID。

CAST((select COUNT(*) from Hire_Response WHERE HireID = @acc AND (HireResponse = 0 OR HireResponse = 1)) as FLOAT)/
CAST((select COUNT(*) from Hire_Response WHERE HireID = @acc) as FLOAT) 

我该怎么做？ 谢谢。

Answer 1

这应该这样做

select distinct 
    a.HireLastName, 
    a.HireFirstName, 
    a.HireID, 
    a.Position_ID, 
    a.BarNumber, 
    a.Archived, 
    a.DateArchived, 
    b.Position_Name, 
    CAST((select COUNT(*) from Hire_Response WHERE HireID = a.HireID AND 
     (HireResponse = 0 OR HireResponse = 1)) as FLOAT)/
    CAST((select case when COUNT(*) = 0 then 1 else COUNT(*) end from Hire_Response WHERE HireID = a.HireID) as FLOAT) as mySpecialColumn 
from NewHire a 
join Position b on a.Position_ID = b.Position_ID 
join WorkPeriod c on a.hireID = c.HireID 
where a.Archived = 0 and c.InquiryID is not null 
order by a.HireID DESC, a.HireLastName, a.HireFirstName 

Answer 2

您需要为该列添加别名。 这是假设你的计算是正确的参考你需要的列。

select 
    (Calculated Column expression) as CalculatedColumn, 
    * 
from 
    TableName 


select distinct 
    a.HireLastName, 
    a.HireFirstName, 
    a.HireID, 
    a.Position_ID, 
    a.BarNumber, 
    a.Archived, 
    a.DateArchived, 
    b.Position_Name, 
    (CAST((select COUNT(*) from Hire_Response WHERE HireID = a.HireIDAND (HireResponse = 0 OR HireResponse = 1)) as FLOAT)/
    CAST((select COUNT(*) from Hire_Response WHERE HireID = a.HireID) as FLOAT)) as CalculatedColumn 
from NewHire a 
join Position b on a.Position_ID = b.Position_ID 
join WorkPeriod c on a.hireID = c.HireID 
where a.Archived = 0 and c.InquiryID is not null 
order by a.HireID DESC, a.HireLastName, a.HireFirstName 

Answer 3

你只需要计算添加到您的select语句，因为我已经把下面，我也alaised与列名的计算为您提供：

select distinct 
    a.HireLastName, 
    a.HireFirstName, 
    a.HireID, 
    a.Position_ID, 
    a.BarNumber, 
    a.Archived, 
    a.DateArchived, 
    b.Position_Name, 
    CAST((select COUNT(*) from Hire_Response WHERE HireID = a.HierID AND 
     (HireResponse = 0 OR HireResponse = 1)) as FLOAT)/
    CAST((select COUNT(*) from Hire_Response WHERE HireID = a.HierID) as FLOAT) AS [Calculation] 
from NewHire a 
join Position b on a.Position_ID = b.Position_ID 
join WorkPeriod c on a.hireID = c.HireID 
where a.Archived = 0 and c.InquiryID is not null 
order by a.HireID DESC, a.HireLastName, a.HireFirstName 

Answer 4

艰难地试图找出没有数据结构的例子的目标，但在这里。我添加了一个新的JOIN，和GROUP BY子句：

select distinct 
    a.HireLastName, 
    a.HireFirstName, 
    a.HireID, 
    a.Position_ID, 
    a.BarNumber, 
    a.Archived, 
    a.DateArchived, 
    b.Position_Name, 
    sum(case when hr.HireResponse in (0, 1) then 1.00 else 0.00 end) as Numerator, 
    count(hr.*) as Denominator, 
    sum(case when hr.HireResponse in (0, 1) then 1.00 else 0.00 end)/count(hr.*) as Fraction 

from 
    NewHire a join 
    Position b on a.Position_ID = b.Position_ID join 
    WorkPeriod c on a.hireID = c.HireID inner join 
    Hire_Response hr on a.HireID = hr.HireID 

where 
    a.Archived = 0 
    and c.InquiryID is not null 

group by 
    a.HireLastName, 
    a.HireFirstName, 
    a.HireID, 
    a.Position_ID, 
    a.BarNumber, 
    a.Archived, 
    a.DateArchived, 
    b.Position_Name 

order by 
    a.HireID DESC, a.HireLastName, a.HireFirstName