Except as provided in this code, no certification document shall be granted to any person unless and until he has subscribed to the following oath or affirmation: “I solemnly swear (or affirm) that I will support the Constitution of the United States of America, the Constitution of the State of California, and the laws of the United States and the State of California.” The oath or affirmation shall be subscribed and certified or declared, pursuant to Section 2015. 5 of the Code of Civil Procedure, and shall be filed with the commission. Any certificated person who is a citizen or subject of any country other than the United States, and who is employed in any capacity in any of the public schools of the state shall, before entering upon the discharge of his duties, subscribe to an oath to support the institutions and policies of the United States during the period of his sojourn within the state. Upon the violation of any of the terms of the oath or affirmation, the commission shall suspend or revoke the credential which has been issued.