Question

Which of the following group functions ignore NULL values?
A.MAX
B.COUNT
C.SUM
D.All of the above

Answer 1

Correct Answer:- D) All of the Above

MAX:-

• Max or Maximum is the function that is used in MS-EXCEL for computing the maximum value from given data.
• MAX Function ignore the null values.

COUNT:-

• The count is the function that is used in MS-EXCEL for counting the values from given data.
• COUNT Function ignores the null values.

SUM:-

• SUM is the function that is used in MS-EXCEL for the addition of the values in given data.
• SUM Function ignore the null values.

So, The Correct Answer:- D)All of the above

Answer 2

MAX, COUNT, SUM are the group functions that ignore NULL values.

D. All of the above

Explanation

When using group functions like MAX, COUNT, and SUM the set of rows that are grouped if it contains NULL values then also it will give us the result.

Extra Information

Group Functions

Group functions are used to group a set of rows which gives us the result according to the group function applied.

The various types of Group Functions are COUNT, MAX, MIN, AVG, SUM, DISTINCT

Examples of Group Function Queries

1. Query for getting the employee's salary which is highest.

SELECT MAX (salary) FROM employee;

2. To get the count of employees in a department

SELECT COUNT (*) FROM employee WHERE dept = 'IT';

3. To get the sum of total salary given to all employees

SELECT SUM (salary) FROM employee;

Query

A query helps us in requesting the data from table or tables of a database.

Example of an SQL query

SELECT * FROM table_name;

In this SELECT is used to select data from the database.

Asterisk (*) is used to retrieve all data from a table.

At the place of table_name, you can write the name of the table present in the database from which you want to retrieve the data.

Database

Database is stored in the computer system which has structured information in organized collections.

There are various types of databases such as

1) Centralized Database

2) Distributed Database

3) Relational Database

4) NoSQL Database

5) Cloud Database

6) Object-oriented Databases

7) Hierarchical Databases

8) Network Databases

Database Management System

Database Management Software is used to store data, retrieve the stored data, and also run queries on data to get specific data according to usage.