单项选择题
A.REVOKE ACCESS ON DATABASE FROM USER bob
B.REVOKE CONNECT ON DATABASE FROM USER tom
C.REVOKE tom FROM ACCESS ON DATABASE BY USER bob
D.REVOKE tom FROM CONNECT ON DATABASE BY USER bob
单项选择题 Which of the following statements is used to revoke all DML privileges on table EMPLOYEE from user TOM?（）
单项选择题 Which of the following privileges permits a user to update the comment on a sequence?（）
单项选择题 Which of the following statements is used to prevent user TOM from adding and deleting data in table TAB1?（）