1Z0-051 QUESTION 13 Q字符的特殊使用

QUESTION 13

View the Exhibit and examine the structure of the PRODUCTS table.

You need to generate a report in the following format:

CATEGORIES

5MP Digital Photo Camera's category is Photo

Y Box's category is Electronics

Envoy Ambassador's category is Hardware

Which two queries would give the required output? (Choose two.)

A. SELECT prod_name ||q'' || 's category is ' || prod_category CATEGORIES  FROM products;

B. SELECT prod_name || q'['s] || 'category is ' ||  prod_category CATEGORIES   FROM products;

C. SELECT prod_name || q'\'s\'  ||  'category is ' || prod_category CATEGORIES    FROM products;

D. SELECT prod_name || q'<'s>'  || 'category is ' ||  prod_category CATEGORIES    FROM products;

答案：CD

解析：

--A选项报错；
SQL> SELECT prod_name ||q'' || 's category is ' || prod_category CATEGORIES  FR
M products;
ERROR:
ORA-01756: 引号内的字符串没有正确结束
--B选项报错；

SQL> SELECT prod_name || q'['s] || 'category is ' ||  prod_categoryCATEGORIES
FROM products;
ERROR:
ORA-01756: 引号内的字符串没有正确结束

--C选项执行正确
SQL> SELECT prod_name || q'\'s\'  ||  'category is ' || prod_category CATEGORIE
    FROM products;

CATEGORIES
-------------------------------------------------------------------------------

test'scategory is testcategory
Envoy Ambassador'scategory is Hardware
Y Box'scategory is Electronics
5MP Digital Photo Camera'scategory is Photo
--D选项执行正确
SQL> SELECT prod_name || q'<'s>'  || 'category is ' ||  prod_category CATEGORIE
    FROM products;

CATEGORIES
-------------------------------------------------------------------------------

test'scategory is testcategory
Envoy Ambassador'scategory is Hardware
Y Box'scategory is Electronics
5MP Digital Photo Camera'scategory is Photo

SQL>