In This Article, You Will Know About SQL Functions.
SQL Functions – Before moving ahead, let’s know a bit about SQL MIN() and MAX() Functions.
Table of Contents
SQL COUNT() Function
The COUNT() function returns the number of records after matching the specified condition.
Syntax
SELECT COUNT(column_name)
FROM table_name
WHERE condition;
SQL AVG() Function
The AVG() function returns the average value of a numerical value’s column.
Syntax
SELECT AVG(column_name)
FROM table_name
WHERE condition;
SQL SUM() Function
The SUM() function returns the total value of a selected numerical value’s column.
Syntax
SELECT SUM(column_name)
FROM table_name
WHERE condition;
Example Database
Below is the example of a database table named “details.”
Id | Name | Class | section_id |
1 | Alex | 5 | 1 |
2 | Rolex | 6 | 2 |
3 | Salex | 7 | 2 |
4 | Lelex | 8 | 3 |
5 | Kelex | 9 | 5 |
SQL COUNT()
Example: Use COUNT() function to return the total number of ‘Class’.
SELECT COUNT(class)
FROM details;
Example: Use COUNT() function to return the total number of ‘Class’ for a specified condition.
SELECT COUNT(class)
FROM details
WHERE section_id = 2;
SQL AVG()
Example: Use AVG() function to return the average value of ‘Class’.
SELECT AVG(class)
FROM details;
As a result, it returns the average value of ‘Class’ column.
Example: Use AVG() function to return the average value of ‘Class’.
SELECT AVG(class)
FROM details
WHERE section_id = 2;
As a result, it returns the average value of ‘Class’ column with a specified condition.
SQL SUM()
Example: Use SUM() function to return the SUM value of ‘Class’.
SELECT SUM(class)
FROM details;
As a result, it returns the sum of ‘Class’ column.
Example: Use SUM() function to return the SUM value of ‘Class’.
SELECT SUM(class)
FROM details
WHERE section_id = 2;
As a result, it returns the SUM value of ‘Class’ column with a specified condition.
If you find anything incorrect in the above-discussed topic and have further questions, please comment below.
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