Verständnisfrage bei Abfrage

[Jumpy]

So vllt.?

SQL-Code:

select
  t1.id_bst, count(t1.Datum) as cntDatum,
  t2.FamName , t2.Adresse, t2.Strasse, t2.KmHome
from
  (Select distinct id_bst, Datum from norbertspringer.tbl_BstAZ
   WHERE Datum between "2015-01-01" and "2015-12-31") t1 
Left Join
  tbl_BstName t2
On t1.id_bst=t2.BstID
Group By
  t1.id_bst, t2.FamName , t2.Adresse, t2.Strasse, t2.KmHome