- Използвайте CTE
with data as (
select
t1.name,
(select count(*) from t2 where t2.name = t1.name) X,
(select count(*) from t3 where t3.name = t1.name) Y
from t1
)
select
data.*,
data.x/data.y as new_calculation
from data
with data as (
select
t1.name,
(select count(*) from t2 where t2.name = t1.name) X,
(select count(*) from t3 where t3.name = t1.name) Y
from t1
)
select
data.*,
data.x/data.y as new_calculation
from data
Грешки в SQL Server при импортиране на CSV файл, въпреки че varchar(MAX) се използва за всяка колона
