Question

I’m stuck with a code. I want to see witch events from a MySQL database are before, after and during an inputted event.

I have a table with the following fields:

• Event_id (int AUTO_INCREMENT)
• start_date (date)
• start_time (varchar)
• end_date (date)
• end_time (varchar)

The start time and end time are in 24 hrs time format, and are stored without the colon separator : (so 23:50 will be stored as 2350, and 1:00 will be stored as 0100)

The dates and time of the inputted event will be in the same formats.

How can I make a query (or script) that get the event that is the closest to the inputted event, a query that check if there are events during the inputted event and a query that get the event closest after the inputted event?

Answer 1

First off, start out by changing your scheme, so you instead have

event_id (int AUTO_INCREMENT),
start_date (timestamp), 
end_date (timestamp)

For your queries, you can now use TIMEDIFF.

Closest event

SELECT *, TIMEDIFF(input_date, start_date) diff
FROM events ORDER BY diff LIMIT 1

That will get you the next event.

Events during event

SELECT * FROM events
WHERE
  TIMEDIFF(input_date, start_date) > 0 AND
  TIMEDIFF(input_date, end_date) < 0
FROM events

That will give you events that are in progress.

You might need to wrap your TIMEDIFFs in SECONDS() before doing the comparison.