SQL GROUP BY Clause

Choose a study mode

Play Quiz

Study Flashcards

Spaced Repetition

Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

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

To filter data based on a specified condition
To sort the result set in ascending order
To retrieve all columns from a table
To get summary data based on one or more groups (correct)

Which aggregate functions can be used with the GROUP BY clause?

COUNT(), MAX(), MIN(), SUM(), AVG() (correct)
UPPER(), LOWER(), CONCAT()
ADD(), SUBTRACT(), MULTIPLY(), DIVIDE()
LENGTH(), TRIM(), REPLACE()

Where should the GROUP BY clause come in relation to the WHERE and HAVING clauses?

Immediately after the SELECT clause
Only after the HAVING clause
Before the WHERE clause if present and after the HAVING clause
After the WHERE clause if present and before the HAVING clause (correct)

What kind of result does the GROUP BY clause return?

A single row for each value of the GROUP BY column (C) Signup and view all the answers

Which columns can be included in the SELECT clause when using the GROUP BY clause?

Only the GROUP BY columns (A) Signup and view all the answers

Give an example of when the GROUP BY query would be used in SQL.

The GROUP BY query would be used to count the number of employees in each department, or to get the department wise total salaries. Signup and view all the answers

What are the aggregate functions that must be used with the GROUP BY clause in the SELECT query?

The aggregate functions that must be used with the GROUP BY clause in the SELECT query are COUNT(), MAX(), MIN(), SUM(), AVG(), etc. Signup and view all the answers

What are the characteristics of the GROUP BY clause in SQL?

The GROUP BY clause is used to form groups of records, must come after the WHERE clause if present and before the HAVING clause, and can include one or more columns to form one or more groups based on those columns. Signup and view all the answers

Can columns other than the GROUP BY columns be included in the SELECT clause? If so, how?

No, only the GROUP BY columns can be included in the SELECT clause. To include other columns, use the aggregate functions like COUNT(), MAX(), MIN(), SUM(), AVG() with those columns. Signup and view all the answers

Explain the purpose of the GROUP BY clause in SQL.

The purpose of the GROUP BY clause is to get summary data based on one or more groups, where the groups can be formed on one or more columns. It returns a single row for each value of the GROUP BY column. Signup and view all the answers