如何在 SQL 中将使用 case 语句制作的 2 个新的附加列放在一起

Question

SELECT 
    ScheduledStartDate, ActualStartDate, ScheduledEndDate, ActualEndDate,
    CASE 
       (WHEN ActualStartDate > ScheduledStartDate THEN 'started late'
        WHEN ActualStartDate < ScheduledStartDate THEN 'started early'
        WHEN ScheduledStartDate = ActualStartDate then 'started on time'
    END AS startDescription )
    ELSE
    CASE 
      (WHEN ActualEndDate < ScheduledEndDate THEN 'finished late'
       WHEN ActualEndDate > ScheduledEndDate THEN 'finished early'
       WHEN ActualEndDate = ScheduledEndDate THEN 'finished on time'
    END AS endDescription )
FROM
    [Production].[WorkOrderRouting];

我制作了 4 列，并想添加 2 列由 'case' 语句制作的新列。

Answer 1

使每个 CASE 表达式成为一个单独的列：

SELECT
    ScheduledStartDate,
    ActualStartDate,
    ScheduledEndDate,
    ActualEndDate,
    CASE WHEN ActualStartDate > ScheduledStartDate THEN 'started late'
         WHEN ActualStartDate < ScheduledStartDate THEN 'started early'
         WHEN ActualStartDate = ScheduledStartDate THEN 'started on time' END AS startDescription,
    CASE WHEN ActualEndDate < ScheduledEndDate THEN 'finished late'
         WHEN ActualEndDate > ScheduledEndDate THEN 'finished early'
         WHEN ActualEndDate = ScheduledEndDate THEN 'finished on time' END AS endDescription
FROM [Production].[WorkOrderRouting];

如何在 SQL 中将使用 case 语句制作的 2 个新的附加列放在一起

How to put together 2 new additional columns made using a case statement together in SQL

sql

case-statement