All officers, whether elected or appointed, shall, before entering upon the duties of their respective offices, take and subscribe to the following oath or affirmation:
I do solemnly swear (or affirm, as the case may be) that I will support the Constitution of the United States and the Constitution of the State of Illinois, and that I will faithfully discharge the duties of the office of , according to the best of my ability.
which oath or affirmation shall be filed in the office of the village clerk. (1965 Code §4.04)