nee heb je, ja kun je krijgen

Etymology
Roughly, “you [already] have [a] 'no', you can [still] get [a] 'yes'”.

Proverb

 * 1) it never hurts to ask

Usage notes

 * This phrase is slightly more specific than its near-synonym (and its synonyms), as this phrase is used specifically when encouraging someone to ask or request things from others, whereas niet geschoten is altijd mis is used when trying things in general (not limited to questions or requests).