c# - LINQ dynamic case -

i have method:

private string getlanguage(string currentlanguage, dynamic entity) {     return (currentlanguage == "de" ? entity.language.german :      currentlanguage == "fr" ? entity.language.french :      currentlanguage == "en" ? entity.language.english :      entity.language.english); } 

and need return linq expression sql statement:

select (case when [french] null [english] else [french] end) language   

how can achieve this?

tks

edit:

to more specific:

i have this:

myid = 1;  objects in context.objects                            objects.id== myid select new                            {                                myobject = new models.myobjects()                                {                                    id = objects.scrid,                                    title = languagefactory.getlabellanguage(objects.labels)                                }                            }).firstordefault(); 

and myobject.title must in language (english, french, dutch, etc.). in sql resolved doing like:

select id, (case when [french] null [english] else [french] end) language  table 

how can linq expression can translated sql query above?

you won't able call arbitrary functions in linq-to-sql. can use expression, this:

private expression<func<dbobject, myobject>> getobjectwithlanguage =     e => new myobject     {         id = e.scrid,         title = e.currentlanguage == "de" ? e.labels.language.german :                 e.currentlanguage == "fr" ? e.labels.language.french :                 e.currentlanguage == "en" ? e.labels.language.english :                 e.labels.language.english     };  ... var results = context.objects.where(e => e.id == myid).select(getobjectwithlanguage); 

this use currentlanguage property on entity determine return. however, if want pass currentlanguage parameter c# code, try this:

private expression<func<dbobject, myobject>> getobjectwithlanguage(string currentlanguage) {     if (currentlanguage == "de")     {         return e => new myobject         {             id = e.scrid,             title = e.labels.language.german         }     }     else if (currentlanguage == "fr")     {         return e => new myobject         {             id = e.scrid,             title = e.labels.language.french         }     }     ... }  var results = context.objects.where(e => e.id == myid).select(getobjectswithlanguage("de")); 

if create general purpose method, suggest use generics rather dynamic parameters, example, suppose have interface like:

public interface ilanguageaware {     string currentlanguage { get; }     string english { get; }     string french { get; }     string german { get; } }  public class objectwithlanguage<t> t : ilanguageaware {     public t originalobject { get; set; }     string languagetext { get; set; } }  public expression<func<t, objectwithlanguage<t>>> getobjectwithlanguage<t>() t : ilanguageaware {     return x => new objectwithlanguage<t>            {                originalobject = x,                languagetext = x.currentlanguage == "de" ? x.german :                               x.currentlanguage == "fr" ? x.french :                               ...            } }  // extension method convenience public static iqueryable<objectwithlanguage<t>> selectwithlanguage<t>(this iqueryable<t> queryable) {     return queryable.select(getobjectwithlanguage<t>()); }  var results = context.objectss.where(e => e.id == myid).selectwithlanguage();