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Node.js - MySQL SELECT DISTINCT statement

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Created by:
Dirask Admin - MR
1340

In this article, we would like to show you how to make MySQL SELECT DISTINCT statement in Node.js.

example data used with SELECT DISTINCT statement
Example data used with SELECT DISTINCT statement - HeidiSQL

Note: at the end of this article you can find database preparation SQL queries.

Practical example

const mysql = require('mysql');

const connection = mysql.createConnection({       // gets connection with database
    host: 'localhost', // '127.0.0.1'
    user: 'root',
    password: 'password',
    database: 'database_name',
});

connection.connect(error => {
    if (error) throw error;
    const query ='SELECT DISTINCT `country` FROM `users`';

    connection.query(query, (error, result) => {  // sends queries
        connection.end();                         // closes connection
        if (error) throw error;
        console.table(result);
    });
});

Result:

┌─────────┬───────────┐
│ (index) │  country  │
├─────────┼───────────┤
│    0    │  'Spain'  │
│    1    │  'Italy'  │
│    2    │ 'Vietnam' │
│    3    │ 'Poland'  │
└─────────┴───────────┘

Database preparation

create_tables.sql file:

CREATE TABLE `users` (
	`id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
	`name` VARCHAR(100) NOT NULL,
	`country` VARCHAR(15) NOT NULL,
	PRIMARY KEY (`id`)
)
ENGINE=InnoDB;

insert_data.sql file:

INSERT INTO `users`
	(`name`, `country`)
VALUES
    ('Tom', 'Poland'),
    ('Chris', 'Spain'),
    ('Jack', 'Spain'),
    ('Kim', 'Vietnam'),
    ('Marco', 'Italy'),
    ('Kate', 'Spain'),
    ('Nam', 'Vietnam');

Node.js - MySQL

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