A.嵌套 B.简单 C.内嵌 D.复杂
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)
A.层次数据库 B.关系数据库 C.非数据库 D.网状数据库
A.Select B.Drop ANY INDEX C.Create VIEW D.Create SESSON