Question

I have a function to which I pass a string and then use linq to entity to check if the string value that I passed already exists in the database. For This purpose I have written this function.

    public static bool UserExistChk(String StrUserId) {
            using (SBVEntities dbcontx = new SBVEntities())
           {
                return dbcontx.Users.Contains(dbcontx.Users.FirstOrDefault(e => e.UserID == StrUserId));

           }
    }

But I get error– Unable to create a constant value of type ‘MySBVApp.Models.User’. Only primitive types (‘such as Int32, String, and Guid’) are supported in this context.

Please help I am new to entity framework and linq.

Answer 1

You can use the Any extension method for this:

public static bool UserExistChk(String StrUserId)
{
  using ( SBVEntities db = new SBVEntities() )
  {
    return db.Users.Any( o => o.UserID == StrUserId );
  }
}