一竿子打翻一船人 [－－－－－－－－]

Jyutping jat1 gon1 zi2 daa2 faan1 jat1 syun4 jan4
Pinyin yī gān zi dǎ fān yī chuán rén

Definitions (Wiktionary)
  1. phrase, figuratively, idiomatic
    to criticize the whole because of one's opinion on a part; to tar with the same brush
    (syn.) 一竹篙打一船人, 一枝竹篙打一船人, 以偏概全