Question

I need to store schedule date and times. Scheduale contains one date field and two time fields.

Is there any possibility to store schedule in one db field and not in two (datetime + datetime)?

I am using SQL Server 2005.

Thanks!

Answer 1

Why would you want to store what are effectively two datetimes in one field rather than two? Are there no cases where the schedule might have times that cross days? (ie. 01/03/2011 23:59, 02/03/2011 01:35)? Do you not mind having to parse out the information rather than having it immediately ready for query?

If you really want to, there’s no reason you can’t store it as a string type, comma separated possibly, maybe XML as suggested, but I can’t say it’s recommended as date/time fields are more space efficient, nice and fast/flexible for searching purposes, and there are many useful T-SQL functions which can easily be used on date/time types which you’d be hard pushed to use on a string without some parsing and casting/converting.

If you can come up with a good reason for not using two datetime fields, I’ll have another Donut! (ps. happy Fat Thursday).

One quick, and horribly evil thought … you could use part of the datetime to store the “difference” … sneak it into the “seconds” and “milliseconds” values, and apply it to the main date/time to get the new value. A bit hacky, but it’d could do the job, depending on your range requirements.

-- Example: 01/03/2011 12:30:02
-- Translates into - first of March 2011, 12:30 to 14:30 (12:30 + (seconds * hours))

set @ModifiedDatetime =
    DATEADD(hour, DATEPART(second, @originalDateTime), @originalDateTime);

Beware of rounding errors with milliseconds … and please think about the consequences of what you’re doing. God kills a kitten each time someone abuses a type 🙂