在另一个字段中创建 Field off Case 语句

Question

我正在尝试找出一个查询来帮助我根据提取的源代码创建一个 AgeBucket 字段。目前，我创建了一个名为 BusinessAge 的字段，它基本上计算从给定请求的开始日期算起的工作日数，并尝试解释下面的代码。

CASE WHEN [EndDate] > [StartDate] THEN [BusinessCalendarDayNum] - [BusinessCalendarDayNum]  --End Date - Start Date
     WHEN [EndDate] IS NULL and [StartDate] IS NOT NULL THEN [BusinessCalendarDayNum] - [BusinessCalendarDayNum] -- GetDate - StartDate
     WHEN [EndDate] = [StartDate] THEN 1
     END AS BusinessAge,

根据它 returns 的数字，我想创建一个 AgeBucket 字段...例如...

CASE WHEN BusinessAge >=0 and BusinessAge <6 THEN '0-5' 
     WHEN BusinessAge >5 and BusinessAge <11 THEN '6-10'

等等，有多个条件。

有没有一种方法可以操纵上述查询并制作更复杂的多案例语句，我可以使用它来创建年龄段字段？或者最好的方法是什么？

Answer 1

试试这样想

SELECT  BusinessAge ,
        CASE WHEN BusinessAge >= 0 AND BusinessAge < 6 THEN '0-5'
             WHEN BusinessAge >= 6 AND BusinessAge <11 THEN '6-10'
        END AS AgeBucket, 

FROM (
       SELECT CASE WHEN [EndDate] > [StartDate] THEN [BusinessCalendarDayNum] - [BusinessCalendarDayNum]  --End Date - Start Date
                   WHEN [EndDate] IS NULL and [StartDate] IS NOT NULL THEN [BusinessCalendarDayNum] - [BusinessCalendarDayNum] -- GetDate - StartDate
                   WHEN [EndDate] = [StartDate] THEN 1
              END AS BusinessAge
       FROM TableName
 )t

已更新：

SELECT CASE WHEN [EndDate] > [StartDate] THEN [BusinessCalendarDayNum] - [BusinessCalendarDayNum]  --End Date - Start Date
                   WHEN [EndDate] IS NULL and [StartDate] IS NOT NULL THEN [BusinessCalendarDayNum] - [BusinessCalendarDayNum] -- GetDate - StartDate
                   WHEN [EndDate] = [StartDate] THEN 1
              END AS BusinessAge,
       CASE WHEN 
                CASE WHEN [EndDate] > [StartDate] THEN [BusinessCalendarDayNum] - [BusinessCalendarDayNum]  --End Date - Start Date
                   WHEN [EndDate] IS NULL and [StartDate] IS NOT NULL THEN [BusinessCalendarDayNum] - [BusinessCalendarDayNum] -- GetDate - StartDate
                   WHEN [EndDate] = [StartDate] THEN 1
                END BETWEEN 0 AND 6 
            THEN '0-5'
            WHEN 
                CASE WHEN [EndDate] > [StartDate] THEN [BusinessCalendarDayNum] - [BusinessCalendarDayNum]  --End Date - Start Date
                   WHEN [EndDate] IS NULL and [StartDate] IS NOT NULL THEN [BusinessCalendarDayNum] - [BusinessCalendarDayNum] -- GetDate - StartDate
                   WHEN [EndDate] = [StartDate] THEN 1
                END BETWEEN 6 AND 11 
            THEN '6-11'
        END AS AgeBucket

FROM TableName

在另一个字段中创建 Field off Case 语句

Create Field off Case Statement in Another Field

sql

case-statement

sql-server-2012