051-144

View the Exhibit and examine the structure of the PRODUCTS table.
You want to display the category with the maximum number of items.
You issue the following query:
SQL>SELECT COUNT(*),prod_category_id
FROM products
GROUP BY prod_category_id
HAVING COUNT(*) = (SELECT MAX(COUNT(*)) FROM products);
What is the outcome?
A. It executes successfully and gives the correct output.
B. It executes successfully but does not give the correct output.
C. It generates an error because the subquery does not have a GROUP BY clause.
D. It generates an error because = is not valid and should be replaced by the IN operator.

做实验 SELECT MAX(COUNT(*)) FROM products报C的错了，不报错就加上分组语句
SELECT MAX(COUNT(*)) FROM products group by prod_id就不会报错了