Proper notation for harmonic minor scale sharps on keys that include flats

Hi
In minor scales that include flats, like D-minor, should one note the C# (to have a melodic minor scale) as sharp? This will make the scale look bit odd as you will have Bb, C# D? Or should this be notated as Db (it will sound the same anyway) and have Bb,Db,D in the scale?