8.View the Exhibit and examine the structure of the CUSTOMERS table.

8.View the Exhibit and examine the structure of the CUSTOMERS table.

Which two tasks would require subqueries or joins to be executed in a single statement? (Choose two.)



A.listing of customers who do not have a credit limit and were born before 1980

B.finding the number of customers, in each city, whose marital status is 'married'

C.finding the average credit limit of male customers residing in 'Tokyo' or 'Sydney'

D.listing of those customers whose credit limit is the same as the credit limit of customers residing in the city 'Tokyo'

E.finding the number of customers, in each city, whose credit limit is more than the average credit limit of all the customers

答案：DE

解析：题目问的是ABCD哪个需要子查询

A:select * from customers where nvl(cust_create_limit,0)=0 and cust_year_of_birth<1980

B:select cust_city,count(*) from customers where cust_marital_status = 'married' group by cust_city

C:select avg(cust_create_limit) from customers where cust_gender=0 and cust_city in ('Tokyo','Sydney')

D:select * from customers where cust_create_limit in (select cust_create_limit from customers where cust_city='Tokyo'

E:select cust_city，count(*) from customers where cust_create_limit >(select avg(cust_create_limit) from customers) group by cust_city

因此答案:DE