OCP-1Z0-051-V9.02-59题
来源:互联网 发布:路由器关闭了所有网络 编辑:程序博客网 时间:2024/06/07 12:06
59. View the Exhibit and examine the data in the PRODUCTS table.
You need to display product names from the PRODUCTS table that belong to the 'Software/Other '
category with minimum prices as either $2000 or $4000 and no unit of measure.
You issue the following query:
SQL>SELECT prod_name, prod_category, prod_min_price
FROM products
WHERE prod_category LIKE '%Other%' AND (prod_min_price = 2000 OR
prod_min_price = 4000) AND prod_unit_of_measure <> '';
Which statement is true regarding the above query?
A. It executes successfully but returns no result.
B. It executes successfully and returns the required result.
C. It generates an error because the condition specified for PROD_UNIT_OF_MEASURE is not valid.
D. It generates an error because the condition specified for the PROD_CATEGORY column is not valid.
Answer: A
答案解析:
实验验证:
SELECT prod_name, prod_category, prod_min_price
2 FROM products
3 WHERE prod_category LIKE '%Other%' AND (prod_min_price = 2000 OR
4 prod_min_price = 4000) AND prod_unit_of_measure <> '';
no rows selected
prod_unit_of_measure <> ''; 应该改为is not null
因为prod_unit_of_measure <> ''该条件为假,’’相当于NULL,所以会导致该WHERE子句里所有AND连接的值为假,
虽然执行成功但不会返回结果,正确的条件应该是prod_unit_of_measure is not null。
- OCP-1Z0-051-V9.02-59题
- OCP-1Z0-051-V9.02-1题
- OCP-1Z0-051-V9.02-1题
- OCP-1Z0-051-V9.02-1题
- OCP-1Z0-051-V9.02-11题
- OCP-1Z0-051-V9.02-12题
- OCP-1Z0-051-V9.02-14题
- OCP-1Z0-051-V9.02-15题
- OCP-1Z0-051-V9.02-17题
- OCP-1Z0-051-V9.02-18题
- OCP-1Z0-051-V9.02-21题
- OCP-1Z0-051-V9.02-118题
- OCP-1Z0-051-V9.02-120题
- OCP-1Z0-051-V9.02-32题
- OCP-1Z0-051-V9.02-33题
- OCP-1Z0-051-V9.02-93题
- OCP-1Z0-051-V9.02-94题
- OCP-1Z0-051-V9.02-95题
- 程序 人生 历程
- C++文件操作写入和读取结构体类型
- 理解矩阵
- 黑马程序员 ---面向对象
- windows 添加制定路由通过制定网关出去
- OCP-1Z0-051-V9.02-59题
- 由使用tag 0 引发的问题
- PHP中使用了mcrypt_decrypt函数处理Json串后导致Json_decode返回null问题
- linux下的lcx源码,修改无错可用版
- OpenStack的网络管理指南(5)——网络底层(未完结)
- C语言面试题,自己写库函数(memcpy、strcpy、strcmp....)
- sstream类的详解
- 摩托罗拉推非触控式应用 仅限自家机型使用
- 成员变量、实例变量、类变量、成员方法、实例方法、类方法的区别