SELECT
transactiondate = ISNULL(a.transactiondate,b.transactiondate),
a.TotalwebSales,
b.TotalInHouseSales
FROM (
select transactiondate, count(distinct transactionid) as TotalwebSales
from saletransactions
where transactionstationnumber = web -- ?
and transactiondate = <today> -- ?
group by transactiondate
) a
FULL OUTER JOIN (
select transactiondate, count(distinct transactionid) as TotalInHouseSales
from saletransactions
where transactionstationnumber = local -- ?
and transactiondate = <today> -- ?
group by transactiondate
) b
ON b.transactiondate = a.transactiondate
For fast, accurate and documented assistance in answering your questions, please read this article.
Understanding and using APPLY, (I) and (II) Paul White
Hidden RBAR: Triangular Joins / The "Numbers" or "Tally" Table: What it is and how it replaces a loop Jeff Moden