This works, but nvl AND case seem redundant.
Basically, if null then 'N' else 'Y.

CHICKEN\_HATCH\_DATE is a DATE data type.

```
  select  stricken_chicken_id,
          case nvl(to_char(chicken_hatch_date),'N') 
          when 'N' then 'N'
          else 'Y'
          end chicken_hatch_date              
   from   stricken_chicken;

```