Equivalent of SQL Between Statement Using Linq or a Lambda expression

Question

Don't think this is a repost, difficult to search for the word between because it is used in everything (like searching for AND).

I want to filter a list based on a date range.

I have a list with some dates and I want to filter them by a date range. Is there a Linq or Lambda equivalent of the between statement in SQL.

For example, the code below will not work in Linqpad (or Visual Studio):

void Main()
{
    List<ListExample> list = new List<ListExample>();

    list.Add(new ListExample("Name1","23 Aug 2010"));
    list.Add(new ListExample("Name2","23 Aug 2009"));

    var query = from l in list
        where l.DateValue between "01 Jan 2010" and "01 Jan 2011"
        select l;

}

public class ListExample
{

    public ListExample(string name, string dateValue)
    {
        Name = name;
        DateValue = DateTime.Parse(dateValue);
    }

    public string Name{get;set;}
    public DateTime DateValue{get;set;}
}

looks like a duplicate of: http://stackoverflow.com/questions/1447635/linq-between-operator — Piotr Czapla, Nov 03 '10 at 13:47

Ani · Accepted Answer · 2012-07-04T10:51:04.110

28

Something like this?

var query = from l in list
            where l.DateValue >= new DateTime(2010, 1, 1) 
               && l.DateValue <= new DateTime(2011, 1, 1)
            select l;

You can write your own extension method:

public static bool IsBetween(this DateTime dt, DateTime start, DateTime end)
{
   return dt >= start && dt <= end;    
}

In which case the query would look something like (method syntax for a change):

var start = new DateTime(2010, 1, 1);
var end = new DateTime(2011, 1, 1);
var query = list.Where(l => l.DateValue.IsBetween(start, end));

I see you've provided some samples with the dates as strings. I would definitely keep the parsing logic (DateTime.ParseExactor other) separate from the query, if at all possible.

edited Jul 04 '12 at 10:51

answered Nov 03 '10 at 13:09

Ani

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Thanks I was having problems with the >= and needing to create a DateTime. I find Linq a little confusing because they changed the syntax. – Simon Nov 03 '10 at 13:17
@Simon: Cheers. The `>=` doesn't have much to do with LINQ; it's an overloaded operator on `DateTime.` You can use `DateTime.CompareTo` or similar if you prefer. – Ani Nov 03 '10 at 13:19
Thanks Ani - the DateTime.Parse was just for my example in LinqPad as I did not want to post a clients code onto the internet. – Simon Nov 03 '10 at 13:24
the only thing i've done is to change the extention function to stattic for global usage – Tzvi Gregory Kaidanov Jul 04 '12 at 10:30
How would you rewrite your extension method to support Linq to Entities? – Renato Heeb Jun 10 '16 at 09:08

score 1 · Answer 2 · answered Nov 03 '10 at 13:10

1

var query = from l in list
        where new DateTime(1,1,2010) <= l.DateValue and DateValue <= new DateTime(1,1,2011)
        select l;

of course, normally warning about timezones and different times on clients and servers apply

answered Nov 03 '10 at 13:10

kͩeͣmͮpͥ ͩ

7,783
26
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Looks like the extension methods are not supported by Linq to Entities if I link to the entity framework. Does this sound correct or am I missing something. – Simon Nov 03 '10 at 15:18
1

NotSupportedException: Method 'Boolean IsBetween(System.Nullable`1[System.DateTime], System.DateTime, System.DateTime, Boolean)' has no supported translation to SQL. – Simon Nov 03 '10 at 15:43

score 1 · Answer 3 · answered Nov 03 '10 at 13:11

Datetime DT1 = DateTime.Parse("01 Jan 2010");
Datetime DT2 = DateTime.Parse("01 Jan 2011");
var query = from l in list
            where l.DateValue >= DT1 && l.DateValue <= DT2
            select l;

in linq you use the && and || like you would in a normal boolean statement of C#.

Equivalent of SQL Between Statement Using Linq or a Lambda expression

3 Answers3

Linked