pl/sql之savepoint小例子

DECLARE
     v_number number;
BEGIN
     v_number := 1;
     insert into t11 values(T11_SEQ.nextval,v_number);
     savepoint A;
     insert into t11 values(T11_SEQ.nextval,v_number+1);
     savepoint B;
     insert into t11 values(T11_SEQ.nextval,v_number+2);
     savepoint C;
     rollback to B;  
END;