Quiz Discussion

Which of the following is not an aggregate function?

• 1]

  Avg

• 2]

  Sum

• 3]

  With

• 4]

  Min

How can you find rows that do not match some specified condition?

• 1]

  EXISTS

• 2]

  Double use of NOT EXISTS

• 3]

  NOT EXISTS

• 4]

  None of the mentioned

SELECT dept_name, ID, avg (salary)
FROM instructor
GROUP BY dept_name;
This statement IS erroneous because

• 1]

  Avg(salary) should not be selected

• 2]

  Dept_id should not be used in group by clause

• 3]

  Misplaced group by clause

• 4]

  Group by clause is not valid in this query

Subqueries cannot:

• 1]

  Use group by or group functions

• 2]

  Retrieve data from a table different from the one in the outer query

• 3]

  Join tables

• 4]

  Appear in select, update, delete, insert statements.

The ________ keyword is used to access attributes of preceding tables or subqueries in the from clause.

• 1]

  In

• 2]

  Lateral

• 3]

  Having

• 4]

  With

SQL applies predicates in the _______ clause after groups have been formed, so aggregate functions may be used.

• 1]

  Group by

• 2]

  With

• 3]

  Where

• 4]

  Having

Aggregate functions can be used in the select list or the_______clause of a select statement or subquery. They cannot be used in a ______ clause.

• 1]

  Where, having

• 2]

  Having, where

• 3]

  Group by, having

• 4]

  Group by, where

Which of the following creates a temporary relation for the query on which it is defined?

• 1]

  With

• 2]

  From

• 3]

  Where

• 4]

  Select

The EXISTS keyword will be true if:

• 1]

  Any row in the subquery meets the condition only

• 2]

  All rows in the subquery fail the condition only

• 3]

  Both of these two conditions are met

• 4]

  Neither of these two conditions is met