how to user year() and month() functions in NH Criteria API?

Question

I need to use year() and month() functions in Criteria API to be able to express a business filter constrain. Expressions like

cri.Add(Expression.Ge(\"year(         


        

Answer 1

Would something like this work for you?

cri.Add(Expression.Ge("Duration.DateFrom", new Date(fromYear, 1, 1));
cri.Add(Expression.Le("Duration.DateTo", new Date(toYear, 12, 31));

Note that I changed your expression order -- I'm assuming you made a typo and you want to query for dates between DateFrom and DateTo. If the dates contain time data, the second expression would change to:

cri.Add(Expression.Lt("Duration.DateTo", new Date(toYear + 1, 1, 1));

In response to comment:

cri.Add(Expression.Ge("Duration.DateFrom", new Date(fromYear, fromMonth, 1));
// Actual code needs to get last day of to month since it will not always be 31
cri.Add(Expression.Le("Duration.DateTo", new Date(toYear, toMonth, 31));

Is your user input in the form "YYMM"? If that's the case, then you just have to parse out year and month from that string to create fromYear, fromMonth, etc.

Edit: my 3rd and final attempt:

// First parse the input, e.g: september 2009 into 9 (inMonth) and 2009 (inYear)
var fromDate = new DateTime(inYear, inMonth, 1);
var toDate = fromDate.AddMonths(1).AddDays(-1);

cri.Add(Expression.Ge("Duration.DateFrom", fromDate));
cri.Add(Expression.Le("Duration.DateTo", toDate));