Question

I have 2 tables, let says the first table named “Schedule” and the second named “Setting”.

TABLE “SCHEDULE”

 ID    Name    StartTime    EndTime     Room  
---------------------------------------------
 111   AAAA    08:00        09:00       -
 112   BBBB    08:00        09:00       -
 113   CCCC    08:00        09:00       -
 114   DDDD    08:30        09:30       -
 115   EEEE    08:30        09:30       -   
 116   FFFF    08:30        09:30       -      

TABLE “SETTING”

 ID    Type    Room  
------------------------
 111     1     BPD01  
 112     2     BPR33  
 113     2     BPR33  
 114     2     BPR35  
 115     2     BPR33  

I want to get the result like:

 Room    StartTime  EndTime  Total Used   
---------------------------------------
 BPR33   08:00      09:00    2           
 BPR33   08:30      09:30    1           
 BPR35   08:30      09:30    1               

I have the code like:

SELECT ST.Room, S.StartTime, S.EndTime, COUNT(*) AS [Total Used]
FROM Schedule AS S CROSS JOIN Setting AS ST
WHERE (ID IN
  (SELECT ID FROM Setting
   WHERE (Type = '2')))
GROUP BY ST.Room, S.StartTime, S.EndTime

But the code resulted in showing all of the record in Setting with the counted value, the filter does not run properly.

How to do that?

Answer 1

I see a few potential issues here:

• Your WHERE ID IN (SELECT ID FROM Setting WHERE Type='2') looks like it could just be WHERE Type='2'
• What data type is your Type column? If it is INT, do WHERE Type = 2 as opposed to WHERE Type = '2' (which you’d use if Type was VARCHAR).
• You do not appear to have a JOIN condition linking your two tables together (e.g. WHERE S.ID = ST.ID)

All together now:

SELECT ST.Room, S.StartTime, S.EndTime, COUNT(*) AS [Total Used]
FROM Schedule AS S CROSS JOIN Setting AS ST
WHERE S.ID = ST.ID 
AND Type = 2
GROUP BY ST.Room, S.StartTime, S.EndTime