A.11 B.12 C.13 D.14
A.EMPTY(.NULL.) B.LIKE("ABC","AB?") C.AT("A","123ABC") D.EMPTY(SPACE(2))
A.BOF B.CTOD("01/01/2003") C.AT("人民","中華人民共和國(guó)") D.SUBS(DTOC(DATE()),7)