Question

I have two querys:

Select trunc(create_dtime) as Day, Count(Player_Id) as New_Users
From Player
Where Trunc(Create_Dtime) >= To_Date('2012-Jan-01','yyyy-mon-dd')
Group By Trunc(Create_Dtime)

and

Select trunc(create_dtime) as Day,Count(Player_Id) as Retained_Users
From Player
Where Trunc(Create_Dtime) >= To_Date('2012-Jan-01','yyyy-mon-dd')
And Trunc(Init_Dtime)  >= Trunc(Sysdate) - 7
Group By Trunc(Create_Dtime)
Order By Day Asc

Every day has a value, and I want to join these two queries together so I only have one query instead of two.

Answer 1

You shouldn’t need a join there:

SELECT
  TRUNC(CREATE_DTIME) AS DAY,
  COUNT(PLAYER_ID) AS NEW_USERS,
  COUNT(CASE WHEN TRUNC(INIT_DTIME) >= TRUNC(SYSDATE) - 7 THEN PLAYER_ID ELSE NULL END)     AS RETAINED_USERS
FROM PLAYER
WHERE TRUNC(CREATE_DTIME) >= TO_DATE('2012-Jan-01','yyyy-mon-dd')
GROUP BY TRUNC(CREATE_DTIME)
ORDER BY 1