Cannot convert type 'System.Linq.IQueryable' to 'int'

You may have encountered Cannot convert type 'System.Linq.IQueryable' to 'int' compile time issue in Linq queries. Have a look on bellow example:

Because, Linq query is lazy, and executes only after you request the value. So, If you want to get exact value use FirstOrDefault() as shown below;

 private void GetUserInspectionReminderConfigurations(string relatedTable, int relatedID)
 {
    int codeID = (from c in _context.Codes
                  join h in _context.CodeHeaders on c.CodeHeaderID equals h.CodeHeaderID
                  where (h.CodeTable == "NotificationTypes" && c.CodeValue == "INSPECTIONALERT")
                  select c.CodeID).FirstOrDefault();

 }