Question

I need to perform some date operations in ASP.net using C#.

1. The date i would enter should be of format ‘Jul-05’ (mmm-yy Format and type-string)… how can i check with this???? Or how can i validate this with whatever user is entering as a string???

2. After validating that, i need to compare tht with a value in Database(say a column name buy_period which has a value (say) 04/31/2007).

How can i write a Query for comparing both?? (as both dates would be of different formats)

Can u pls help me in this ???

Answer 1

Use the TryParseExact method to validate the string and parse it to a DateTime value:

DateTime month; if (DateTime.TryParseExact('MMM-yy', CultureInfo.InvariantCulture, DateTimeStyles.None, out month)) {    // parsing was successful } 

The DateTime value will use the first day of month and the time 0:00 to fill up a complete value, so a string like 'jul-05' will be parsed into a complete DateTime value like 2005-07-01 00:00:00.0000, so it will be the starting point of that month.

To compare this to a date in the database you also need the starting point of the next month, which you get with:

DateTime nextMonth = month.AddMonths(1); 

Now you can just compare a date to the starting and ending point of the month in this manner:

where date >= @Month and date < @NextMonth