Invalid expression term error in the code

   L
      var surveys = (from su in DbContext.Surveys
                               where su.userName == su.userName 
                               select su.ID);
if(surveys.Count() > 0)
            {
             int id = 0;
             int.TryParse(surveys.First(), out id);
               return id;
             }
             return 0;

Remove int from TryParse();

int.TryParse(surveys.First(), out int id);

should be

int.TryParse(surveys.First(), out id);

Change :-

List<SurveyContext> surveys = (from su in DbContext.Surveys
                                          where su.userName == su.userName 
                                          select su.ID).ToList();

to

List<string> surveys = (from su in DbContext.Surveys
                                          where su.userName == su.userName 
                                          select su.ID);

You are trying to select string type in Linq and putting it in List<SomeType> which should be List<int> .

  var surveys = (from su in DbContext.Surveys
                                              where su.userName == su.userName 
                                              select su.ID);

  //Code follows
  int.TryParse(surveys.First(), out id);

It sounds like you want something like this. Move the int datatype to the declaration of the variable, and add a property field name after the First() method. (or whatever equivalent property you have on the Survey object that holds its Id)

if(surveys.Count() > 0)
{
    int id = 0;
    int.TryParse(surveys.First().Id, out id);
    return id;
}
return null;

UPDATE : I see you've updated the question, it looks like what you have should do the trick..

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