c# - OData v4 filter query fails when using contains on calculated property -

so have code first ef 6 layer has contact class of:

public class contact {     [key]     public int id { get; set; }      [maxlength(50)]     public string prefix { get; set; }      [maxlength(50)]     public string suffix { get; set; }      [maxlength(50)]     public string firstname { get; set; }      [maxlength(50)]     public string middlename { get; set; }      [maxlength(50)]     public string lastname { get; set; }      [notmapped]     [displayname("full name")]     public string fullname     {                 {             string tempname =                 (!string.isnullorempty(prefix) ? prefix + " " : "") +                 (!string.isnullorempty(firstname) ? firstname + " " : "") +                 (!string.isnullorempty(middlename) ? middlename + " " : "") +                 (!string.isnullorempty(lastname) ? lastname + " " : "") +                 (!string.isnullorempty(suffix) ? suffix + " " : "");             return tempname.trim();         }     }      [maxlength(50)]     public string jobtitle { get; set; }      public bool? primary { get; set; }     public bool? inactive { get; set; }      public int? customer_id { get; set; }      [foreignkey("customer_id")]     public virtual customer customer { get; set; }      public virtual icollection<email> emails { get; set; }     public virtual icollection<address> addresses { get; set; }     public virtual icollection<phonenumber> phonenumbers { get; set; }     public virtual icollection<note> notes { get; set; } } 

i have asp.net web api 2 service running offers list of contacts, when perform odata query of $filter=contains(tolower(fullname), tolower('smith')) badrequest response. verified in webapi method getting results database, sends badrequest error.

it has fullname field either being calculated field or because has notmapped attribute. when change odata query $filter=contains(tolower(lastname), tolower('smith')) works fine. tried using display name of "full name" in query instead of "fullname" , did not work.

is there need make odata play nice calculated or notmapped field?

implement odata function on contactscontroller takes string comparison , returns filtered set of contacts. like:

    [httpget]     [odataroute("contacts/default.fullnamecontains(value={value})")]     public ihttpactionresult fullnamecontains(string value)     {         value = value.tolower();         return ok(db.contacts.tolist().where(c => c.fullname.contains(value)));     } 

because fullname computed, function must perform filtering in memory.