Question

I I build select and where condition against an entity ObjectSet class using
ObjectQuery.

  ObjectQuery<DbDataRecord> query = context.TestEnt.Select("it.BuySell, "
                        + "it.DepoTerm").Where("Datediff(day,it.RunDateTime,'22-11-2012')=0" );

                var a = query.ToList();
                foreach (var tmp in a)
                {
                    Console.WriteLine(tmp["BuySell"].ToString());
                }

I would like to use datediff function in my where contition ,
How can I do it ?

Answer 1

Try this:

var query = context.TestEnt
                   .Where("DiffDays(it.RunDateTime,'22-11-2012')=0" );
                   .Select("it.BuySell, it.DepoTerm")

It is possible that you will have to call CreateDataTime on your string passed data to make it work. Here is list of all supported date functions in ESQL.

You can also use Linq-to-entities:

var query = context.TestEnt
                   .Where(x => SqlFunctions.DateDiff("day", x.RunDateTime,'22-11-2012') == 0)
                   .Select(x => new { x.BuySell, x.DepoTerm });