Oracle默认HR用户下，如下3个SQL分别返回的结果条目数是多少？B 1、select * from emp where 1=2; 2、select min(sal) from emp where 1=2; 3、select deptno,min(sal) from emp where 1=2 group by deptno; A 0,1,1 B 0,1,0 C 0,0,1 D 0,0,0