SQL JOIN WITH A BUFFER TIME - sql

Question

I have tWO tables and have to check whether the time in a table lies in between range of other table.
ProgStartTime gives the start time of the range and ProgEndTime gives end of the range which lies in MBA table.
Am checking whether the AdvTime in MAP table exists in between the ProgStartTime and ProgEndTime from MBA table.
For time range less than one hour i have to give a buffer of + or - 5 mins.
i.e if ProgStarttTime is 18:00 & progEndTime is 19:00 & AdvTime is 17:55/19:05 it should match the range.
Whereas if ProgStarttTime is 18:00 & progEndTime is 20:00 & AdvTime is 17:55 it shouldnt match.
Sorry for the clumsy content am in bit of a hurry.
I used the below query for joining wihtout buffer time
SELECT DISTINCT mb.Id AS mbaid,
mp.id AS mapid,
mp.Channel AS Channel,
mp.Product,
mp.ProgDate,
mp.AdvTime,
mb.Channel,
mb.ProgStartTime,
mb.ProgEndTime,
convert(time, dateadd(MINUTE, datediff(MINUTE, mb.progStartTime, mb.progEndTime), 0)) AS timeDiff
FROM map22 AS mp
INNER JOIN mba22 AS mb ON ((mp.ProgDate = mp.ProgDate
AND mp.Channel=mb.Channel
AND mp.Product=mb.Product))
WHERE (mp.ProgDate = mb.ProgDate
AND AdvTime >= ProgStartTime
AND (AdvTime <= ProgEndTime
OR ProgEndTime < ProgStartTime))
OR (mp.ProgDate = Dateadd(DAY,1,mb.ProgDate)
AND ProgEndTime < ProgStartTime
AND AdvTime <= ProgEndTime)
ORDER BY mp.Id ASC

Answer 1

Your sample query has a lot going on, so I've created a simplified example.
Set up the data:
create table MBA (MBAID int, ProgStartTime datetime, ProgEndTime datetime)
insert into MBA select 1, '20130318 18:00:00', '20130318 19:00:00'
insert into MBA select 2, '20130318 18:00:00', '20130318 20:00:00'
create table Map (MapID int, AdvTime datetime)
insert into Map select 1, '20130318 17:55:00'
insert into Map select 2, '20130318 18:30:00'
insert into Map select 3, '20130318 19:05:00'
insert into Map select 4, '20130318 20:05:00'
Based on this, we can apply a CASE statement to give AdvTime more loose matching when the difference between the dates is an hour or less:
select *
from MBA
inner join Map on
MBA.ProgStartTime <=
case when datediff(mi, MBA.ProgStartTime, MBA.ProgEndTime) <= 60
then dateadd(mi, 5, Map.AdvTime)
else Map.AdvTime
end
and MBA.ProgEndTime >=
case when datediff(mi, MBA.ProgStartTime, MBA.ProgEndTime) <= 60
then dateadd(mi, -5, Map.AdvTime)
else Map.AdvTime
end
Gives results:
We can see that for MBA 1, which has an hour duration, we are matching AdvTime values slightly before and after, but for MBA 2, only matching those within the time period as required.
SQL Fiddle with demo.
Edit after comment:
Added another example for the values in the comments, with following data:
create table MBA (MBAID int, ProgStartTime datetime, ProgEndTime datetime)
insert into MBA select 1, '20130318 21:00:00', '20130318 22:00:00'
create table Map (MapID int, AdvTime datetime)
insert into Map select 1, '20130318 20:55:00'
insert into Map select 2, '20130318 22:05:00'
The original query matches both of the above rows as expected.
SQL Fiddle with demo.
Edit after comment:
Tested with more data:
create table MBA (MBAID int, ProgStartTime datetime, ProgEndTime datetime)
insert into MBA select 1, '20130318 23:00:00', '20130319 02:00:00'
create table Map (MapID int, AdvTime datetime)
insert into Map select 1, '20130319 00:30:00'
Still matching as expected.
SQL Fiddle with demo.
Final edit after comment?
OK, now we know a bit more about the schema we can make one final query. Set up the data:
create table MBA (MBAID int, ProgStartTime datetime, ProgEndTime datetime)
insert into MBA select 1, '18:00:00', '19:00:00'
insert into MBA select 2, '18:00:00', '20:00:00'
insert into MBA select 3, '21:00:00', '22:00:00'
insert into MBA select 4, '23:30:00', '02:00:00'
insert into MBA select 5, '23:30:00', '00:30:00'
create table Map (MapID int, AdvTime datetime)
insert into Map select 1, '17:55:00'
insert into Map select 2, '18:30:00'
insert into Map select 3, '19:05:00'
insert into Map select 4, '20:05:00'
insert into Map select 5, '20:55:00'
insert into Map select 6, '22:05:00'
insert into Map select 7, '23:25:00'
insert into Map select 8, '23:30:00'
insert into Map select 9, '00:30:00'
insert into Map select 10, '00:35:00'
Use the following query:
select *
from MBA
inner join Map on
(MBA.ProgStartTime < MBA.ProgEndTime
and MBA.ProgStartTime <=
case when datediff(mi, MBA.ProgStartTime, MBA.ProgEndTime) <= 60
then dateadd(mi, 5, Map.AdvTime)
else Map.AdvTime
end
and MBA.ProgEndTime >=
case when datediff(mi, MBA.ProgStartTime, MBA.ProgEndTime) <= 60
then dateadd(mi, -5, Map.AdvTime)
else Map.AdvTime
end) or
(MBA.ProgStartTime > MBA.ProgEndTime
and (MBA.ProgStartTime <=
case when 1440 - datediff(mi, MBA.ProgEndTime, MBA.ProgStartTime) <= 60
then dateadd(mi, 5, Map.AdvTime)
else Map.AdvTime
end
or MBA.ProgEndTime >=
case when 1440 - datediff(mi, MBA.ProgEndTime, MBA.ProgStartTime) <= 60
then dateadd(mi, -5, Map.AdvTime)
else Map.AdvTime
end))
We expect the following rows to be matched:
MBA Matched Maps
1 1,2,3
2 2,3
3 5,6
4 8,9,10
5 7,8,9,10
Results:
SQL Fiddle with demo.