You’re only wrong in a few details (from the article linked above):
“A number of measures were introduced at the time, including increased security at schools across the country and a regulation requiring people to register with their national ID cards when buying large knives.”
http://www.britishblades.com/forums/showthread.php?27534-Chinese-Knife-law ~ reflects the rules on the books at the time ~ showing your ID is an add on to other restrictions. See the comments section for this one ~
Obviously they need even more knife control laws.