MariaDB COUNT Function


Objectives

  • Understanding of MariaDB COUNT Function

  • MariaDB COUNT Function Exercise


Create database and table and insert data if it is not created already

--- Create database if not exist
CREATE DATABASE IF NOT EXISTS mariadb_tutorial;

--- Select the database for further operation
USE mariadb_tutorial;

--- Create table if not exist
CREATE TABLE IF NOT EXISTS person (
    id int(12) NOT NULL AUTO_INCREMENT,
    first_name varchar(150) NOT NULL,
    last_name varchar(150),
    email varchar(100),
    age int,
    income double,
    PRIMARY KEY (id)
)

--- Remove old Data
TRUNCATE person;

--- Insert data into table if not exist
INSERT INTO person (first_name, last_name, email, age, income)
VALUES
	('Faiyaz', 'Mia', 'faiyaz@pf.local', 1, 5000),
	('John', 'Doe', 'john@pf.local', 19, 100),
	('Tahsin', NULL, 'tahsin@pf.local', 10, 150),
	('Jane', 'Doe', 'jane@gmail.com', 26, 300),
	('Rakib', 'Mia', 'rakib@bf.local', 24, 200),
	('Sagor', 'Sowrov', 'email10@bf.local', 20, 250),
	('Touhid', NULL, 'hmtmcse.com@gmail.com', 30, 500);


Understanding of MariaDB COUNT Function

COUNT() function count the number of row come from the query (SELECT) result. The query result could be filtered by various WHERE condition, could be not.


MariaDB COUNT Function Exercise

Problem: Find person total number

Syntax

SELECT COUNT(*) FROM person;

Example

SELECT * FROM person WHERE first_name LIKE "t%";

Output

+----------+
| COUNT(*) |
+----------+
|        7 |
+----------+
1 row in set (0.109 sec)


MariaDB COUNT Function Video tutorial

Share