前功尽弃 (前功盡棄) qián gōng jìn qì

qián gōng jìn qì set phrase to waste all previous labor
Domain: Idiom 成语
Notes: (CC-CEDICT '前功盡棄'; Guoyu '前功盡棄'; Mathews 1931 '前功盡棄', p. 126)