sql - 如何计算此查询给出的结果数

Question

with events as (select count(distinct b."SubstituteTeacher"), row_number() over (partition by b."SubstituteTeacher" order by d."StartTime") as seq from dbo."Accounts" a

full outer join dbo."WorkContracts" b on a."ID" = b."SubstituteTeacher" . 

full outer join dbo."SubstituteTeacherPeriods" c . 
on a."ID" = c."SubstituteTeacher" . 

full outer join dbo."OrderPeriods" d . 
on a."ID" = d."CreatedBy"

full outer join dbo."Addresses" e . 
on a."Address" = e."ID"

full outer join dbo."StandardCities" f
on e."City" = f."ID"

full outer join dbo."Orders" g
on d."Order" = g."ID" 

where a."ID" != 16 and a."ID" != 11797 

and b."WorkContractType" != 3 

group by d."StartTime", b."SubstituteTeacher")

select * from events where seq = 1 ;

标签： sqlpostgresqlgroup-bycount

Answer 1

从 seq = 1 的事件中选择 Count(*)