Group Functions

Which of the following is NOT a GROUP BY function?

• MAX

• MIN

• NVL

• AVG

Which of the following functions can be used without GROUP BY clause in SELECT query? (Select all that apply)

• COUNT

• MAX

• MIN

• AVG

A table T_COUNT has 12 number values as 1, 2, 3, 32, 1, 1, null, 24, 12, null, 32, null. Predict the output of the below query.

SELECT COUNT (*) FROM t_count;

• 12

• 6

• 9

• Throws exception because COUNT function doesn't works with NULL values

A table T_COUNT has 12 number values as 1, 2, 3, 32, 1, 1, null, 24, 12, null, 32, null. Predict the output of the below query.

SELECT COUNT (num) FROM t_count;

• 12

• 6

• 9

• Throws exception because COUNT function doesn't works with NULL values

What happens when the below query is executed in SQL* Plus?

SELECT COUNT() FROM dual;

• Executes successfully and returns no output

• Executes successfully and returns output as '1'

• Throws exception "ORA-00909: invalid number of arguments"

• Throws exception "ORA-00904: "COUNT": invalid identifier" because COUNT function doesn't works with DUAL table

Which of the following is a valid SELECT statement?

• SELECT AVG(retail-cost) FROM books GROUP BY category;
  

• SELECT category, AVG(retail-cost) FROM books;
  

• SELECT category, AVG(retail-cost) FROM books WHERE AVG(retail-cost) > 8.56 GROUP BY category;
  

• SELECT category, AVG(retail-cost) Profit FROM books GROUP BY category HAVING profit > 8.56;
  

Which of the following functions is used to calculate the total value stored in a specified column?

• COUNT

• ADD

• TOTAL

• SUM

Which of the following SELECT statements lists the highest retail price of all books in the Family category?

• SELECT MAX(retail) FROM books WHERE category = 'FAMILY';
  

• SELECT MAX(retail) FROM books HAVING category = 'FAMILY';
  

• SELECT retail FROM books WHERE category = 'FAMILY' HAVING MAX(retail);
  

• None of the above

Which of the following functions can be used to include NULL values in calculations?

• SUM

• NVL

• MAX

• MIN

Which of the below clauses is used to group a set of rows based on a column or set of columns?

• HAVING

• WHERE

• GROUP BY

• GROUPING