MULTIPLE_CHOICE_MORE_THAN_ONE_ANSWER:Integrity check and control of the guard object () to prevent them from entering the database. The object of security control is () to prevent them from accessing database data.

Integrity check and control of the guard object () to prevent them from entering the database. The object of security control is () to prevent them from accessing database data. 　 *@[ABCD](4) A. Non semantic data B. Illegal users C. Incorrect data D. Illegal operation



A. Non semantic data
B. Illegal users
C. Incorrect data
D. Illegal operation


answer：A B C D