第18题: [单项选择]假如只想显示视图:EMPLOYEE_HIST的名字、视图的定义和视图定义的长度,请问应该使用以下SQL语句中的哪一个 A. SELECT B. SELECT C. SELECT D. SELECT VIEW 参考答案:B 答案解析:[解析] 这一题是测试对通过查询数据字典user_views获取视图信息的熟悉程度。根据有关通过查询数据字典user_views获取视图信息的介绍,可知能够满足本题要求的查询语句只有选项B。
第35题: [单项选择]A vessel towing is showing three forward white masthead lights in a vertical line. This means that the length of the(). A. towing vessel is less than 50 meters B. towing vessel is greater than 50 meters C. tow is less than 200 meters D. tow is greater than 200 meters 参考答案:D