Question

我有此代码，每个月都要检查一次，以查看该人是否在该月入学，最后要告诉您该人是否已入学整年。 Annual每月检查一次，以查看案例表达式中是否有1。问题是我无法让SQL识别Jan和Feb

之类的别名

Select SSN, FirstName, LastName,
  Case (DateEnrolled > '1-1-2019' and DateEnrolled < '1-31-2019' ) then 1 else 0 as [Jan],
  Case (DateEnrolled > '2-1-2019' and DateEnrolled < '2-28-2019') then 1 else 0 as [Feb],
  ...
  Case (Jan = 1 AND Feb = 1 AND...) then 1 else 0 as [Annual]
from EmployeePerson

Answer 1

尝试一下：

with cte as
(
Select SSN, FirstName, LastName,
  Case (DateEnrolled > '1-1-2019' and DateEnrolled < '1-31-2019' ) then 1 else 0 end as [Jan],
  Case (DateEnrolled > '2-1-2019' and DateEnrolled < '2-28-2019') then 1 else 0 end as [Feb],
  ...
from EmployeePerson
)

select SSN, FirstName, LastName, [Jan], [Feb]...,[Dec],
Case (Jan = 1 AND Feb = 1 AND...AND [Dec] = 1) then 1 else 0 end as [Annual]
from cte

Answer 2

试试看！ SELECT SSN，FirstName，LastName，案例（日期注册> '01 -01-2019'和日期注册<'01 -31-2019'）然后是'简'，案例（日期注册> '02 -01-2019'和日期注册<'02 -28-2019'）然后是'二月' 结束为“年度” 来自EmployeePerson;

我认为这会有所帮助。

Answer 3

尝试

select SSN, FirstName,
Case when Jan is null then 0 else 1 end as Jan,
Case when Feb is null then 0 else 1 end as Feb,
Case when Mar is null then 0 else 1 end as Mar,
Case when Apr is null then 0 else 1 end as Apr,
Case when May is null then 0 else 1 end as May,
Case when Jun is null then 0 else 1 end as Jun,
Case when Jul is null then 0 else 1 end as Jul,
Case when Aug is null then 0 else 1 end as Aug,
Case when Sep is null then 0 else 1 end as Sep,
Case when Oct is null then 0 else 1 end as Oct,
Case when Nov is null then 0 else 1 end as Nov,
Case when [Dec] is null then 0 else 1 end as [Dec],
Case when ([Jan] is not null AND [Feb] is not null AND [Mar] is not null AND 
    [Apr] is not null AND [May] is not null AND [Jun] is not null AND 
    [Jul] is not null AND [Aug] is not null AND [Sep] is not null AND 
    [Oct] is not null AND [Nov] is not null AND [Dec] is not null) then 1 else 0 end as Annual
from(
Select SSN, FirstName, format(DateEnrolled, 'MMM') Enrolled
from EmployeePerson)aa 
pivot (max(Enrolled) for Enrolled in([Jan], [Feb], [Mar], [Apr], [May], [Jun], [Jul], [Aug], [Sep], [Oct], [Nov], [Dec])) as dtl

在案例表达式中调用别名

3 个答案: