SQL Quiz

What is the purpose of the GROUP BY clause in SQL?

• To group rows that have the same values into summary rows

• To filter rows based on a condition

• To sort rows in ascending order

• To join multiple tables

Which of the following is an aggregate function in SQL?

• COUNT()

• JOIN()

• SELECT()

• WHERE()

What does the HAVING clause do in SQL?

• It filters records before grouping

• It filters records after grouping

• It sorts the results

• It joins two tables

Which statement is true about subqueries?

• They can return multiple columns

• They must be enclosed within parentheses

• They can use ORDER BY

• They cannot be used in WHERE clauses

What type of join returns all rows from both tables when there is a match?

• OUTER Join

• INNER Join

• CROSS Join

• LEFT Join

What does a LEFT OUTER join return?

• Only matching rows from both tables

• All rows from the right table

• All rows from the left table and matching rows from the right table

• Only unmatched rows

Which SQL command is used to create a view?

• CREATE VIEW

• CREATE TABLE

• SELECT INTO

• INSERT INTO

In a CROSS join, what is produced?

• Only matching records

• A Cartesian product of two or more tables

• A filtered set of records

• An aggregated result

What is a characteristic of an OUTER join?

• It only returns matching records.

• It returns unmatched records from one or both tables

• It cannot be used with aggregate functions.

• It requires a common attribute name.

Which SQL clause is used to filter results after grouping?

• WHERE

• HAVING

• ORDER BY

• GROUP BY