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I am not sure where to post this question, I also hope I worded it correctly.

I need help with sql, story below:

I have an table with starts and end date, including time(Like timetable). It’s working fine. I have issues conflicts.

Let’s say I have sql table with the below informa information:
StartDate: EndDate
23 March 2012 10:00pm 23 March 2012 11:00pm
23 March 2012 14:00pm 23 March 2012 16:00pm
23 March 2012 17:00pm 23 March 2012 18:00pm

I want to add an event with no conflict – that where the problem is!

Lets assume the new event has same start date, but time from 12:00 to 15:00
I am expecting a conflict as the end time (15:00) overlapse the 14:00 (second row)

Here is what I did
I checked if start date exists like
WHERE StartDate = @StartDate

23 March 2012 14:00pm 23 March 2012 16:00pm
23 March 2012 17:00pm 23 March 2012 18:00pm

If I extend by checking if end date not between any dates
WHERE StartDate = @ StartDate
AND ((EndDate BETWEEN @ StartDate AND @EndDate OR EndDate = @ EndDate OR EndDate >@ EndDate))

It works but will have another issue when StartDate is between an event, let’s say 15pm. It's been hours trying to solve this...

Here is the procedure I wrote, but still can't avoid some duplicates:
  WHERE StartDate = @StartDate
    AND ((@EndDate BETWEEN StartDate AND EndDate OR EndDate = @EndDate OR EndDate > @EndDate))

Thanking you in advance, I have googled possible solutions and cant fin one that closer to mine.
Updated 7-Jun-21 0:14am
Boipelo 23-Mar-12 6:24am    
Let me clarify something… I using select because I want to check if there are any rows before saving.
Member 11811228 3-Jul-15 7:13am    
i need a coding in all of three i.e jsp,html and sql for shar fire call in one program
Boipelo 24-Jul-15 13:38pm    
Solution 1 has is your answer. No jsp needed.

Try below and let me know if this works for your requirement.

  WHERE ((StartDate > @StartDate AND EndDate < @StartDate) -- Starts within an already used time slot
(StartDate < @EndDate AND EndDate > @EndDate))-- Ends within an already used time slot
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Boipelo 26-Mar-12 5:16am    
Thanks for taking your time to help me, I have posted the final solution.
Saral S Stalin 26-Mar-12 6:09am    
No probs Bro.. Happy to help :)
@Saral S Stalin, thanks for your assistance... your solution works with these minor adjustments

 WHERE ((StartDate <= @StartDate AND EndDate > @StartDate) -- Included the start date to avoid duplicates start date and also changed the '>' to '<' after AND, it was not within
  (StartDate < @EndDate AND EndDate >= @EndDate))-- The range was perfect, I just included the EndDate so that we dont have events ending at the same time.

Thanks once more for your solution... you gave me direction
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You can check if two dates lies between two dates by following query

SELECT * FROM [vacation]
where ((DATEDIFF(d,'2021-06-30',startdate) <= 0 and DATEDIFF(d,'2021-07-10',enddate) >= 0) or
(DATEDIFF(d,'2021-06-30',startdate) <= 0 and DATEDIFF(d,'2021-07-10',enddate) >= 0))
OR ((startdate between '2021-06-30' and '2021-07-10') or (enddate between '2021-06-30' and '2021-07-10'))
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