您要对EMPLOYEES表的FIRST_NAME和LAST_NAME列创建一个组合索引。以下哪条语句将完成此任务()
A:CREATE INDEXfl_idx ON employees(first_name last_name)
B:CREATE INDEXfl_idx ON employees(first_name),employees(last_name)
C:CREATE INDEXfl_idx ON employees(first_name,last_name)
D:CREATE INDEXfl_idx ON employees(first_name);CREATE INDEXfl_idx ON employees(last_name)
出自:计算机科学