How to Connect
- Connecting with Node.js
- Connecting with Python
- Connecting with PHP
- Connecting with Go
- Connecting with Java
Connecting with Node.js
This guide explains how to establish a connection between a Node.js application and a MySQL database using the mysql2
package. It walks through the necessary setup, configuration, and execution of a simple SQL query.
Variables
Certain parameters must be provided to establish a successful connection to a MySQL database. Below is a breakdown of each required variable, its purpose, and where to find it. Here’s what each variable represents:
Variable |
Description |
Purpose |
---|---|---|
|
MySQL username, from the Elestio service overview page |
Identifies the database user who has permission to access the MySQL database. |
|
MySQL password, from the Elestio service overview page |
The authentication key is required for the specified USER to access the database. |
|
Hostname for MySQL connection, from the Elestio service overview page |
The address of the server hosting the MySQL database. |
|
Port for MySQL connection, from the Elestio service overview page |
The network port used to connect to MySQL. The default port is 3306. |
|
Database Name for MySQL connection, from the Elestio service overview page |
The name of the database being accessed. A MySQL instance can contain multiple databases. |
These values can usually be found in the Elestio service overview details as shown in the image below, make sure to take a copy of these details and add it to the code moving ahead.
Prerequisites
- Install Node.js and NPM
- Check if Node.js is installed by running:
node -v
- Check if Node.js is installed by running:
-
- If not installed, download it from nodejs.org and install. Additionally, verify npm installation:
npm -v
- If not installed, download it from nodejs.org and install. Additionally, verify npm installation:
- Install the mysql2 Package
- The mysql2 package enables Node.js applications to interact with MySQL. Install it using:
npm install mysql2 --save
- The mysql2 package enables Node.js applications to interact with MySQL. Install it using:
Code
Once all prerequisites are set up, create a new file named mysql.js
and add the following code:
const mysql = require("mysql2");
// Database connection configuration
const config = {
host: "HOST",
user: "USER",
password: "PASSWORD",
database: "DATABASE",
port: PORT,
};
// Create a MySQL connection
const connection = mysql.createConnection(config);
// Connect to the database
connection.connect((err) => {
if (err) {
console.error("Connection failed:", err);
return;
}
console.log("Connected to MySQL");
// Run a test query to check the MySQL version
connection.query("SELECT VERSION() AS version", (err, results) => {
if (err) {
console.error("Query execution failed:", err);
connection.end();
return;
}
console.log("MySQL Version:", results[0]);
// Close the database connection
connection.end((err) => {
if (err) console.error("Error closing connection:", err);
});
});
});
To execute the script, open the terminal or command prompt and navigate to the directory where mysql.js is located. Once in the correct directory, run the script with the command:
node mysql.js
If the connection is successful, the terminal will display output similar to:
Connected to MySQL
MySQL Version: { version: '8.0.41' }
Connecting with Python
This guide explains how to establish a connection between a Python application and a MySQL database using the mysql-connector-python
package. It walks through the necessary setup, configuration, and execution of a simple SQL query.
Variables
Certain parameters must be provided to establish a successful connection to a MySQL database. Below is a breakdown of each required variable, its purpose, and where to find it. Here’s what each variable represents:
Variable |
Description |
Purpose |
---|---|---|
|
MySQL username, from the Elestio service overview page |
Identifies the database user who has permission to access the MySQL database. |
|
MySQL password, from the Elestio service overview page |
The authentication key is required for the specified USER to access the database. |
|
Hostname for MySQL connection, from the Elestio service overview page |
The address of the server hosting the MySQL database. |
|
Port for MySQL connection, from the Elestio service overview page |
The network port used to connect to MySQL. The default port is 3306. |
|
Database Name for MySQL connection, from the Elestio service overview page |
The name of the database being accessed. A MySQL instance can contain multiple databases. |
These values can usually be found in the Elestio service overview details as shown in the image below, make sure to take a copy of these details and add it to the code moving ahead.
Prerequisites
- Install Python
- Check if Python is installed by running:
python --version
- If not installed, download it from python.org and install it.
- Check if Python is installed by running:
- Install the
mysql-connector-python
Package- The mysql-connector-python package enables Python applications to interact with MySQL. Install it using:
pip install mysql-connector-python
- The mysql-connector-python package enables Python applications to interact with MySQL. Install it using:
Code
Once all prerequisites are set up, create a new file named mysql_connect.py
and add the following code:
import mysql.connector
# Database connection configuration
config = {
"host": "HOST",
"user": "USER",
"password": "PASSWORD",
"database": "DATABASE",
"port": PORT
}
try:
# Establish the connection
connection = mysql.connector.connect(**config)
print("Connected to MySQL")
# Create a cursor and execute a test query
cursor = connection.cursor()
cursor.execute("SELECT VERSION()")
# Fetch and print the result
version = cursor.fetchone()
print("MySQL Version:", version[0])
except mysql.connector.Error as err:
print("Connection failed:", err)
finally:
if 'cursor' in locals():
cursor.close()
if 'connection' in locals() and connection.is_connected():
connection.close()
print("Connection closed")
To execute the script, open the terminal or command prompt and navigate to the directory where mysql_connect.py
is located. Once in the correct directory, run the script with the command:
python mysql_connect.py
If the connection is successful, the terminal will display output similar to:
Connected to MySQL
MySQL Version: 8.0.41
Connection closed
Connecting with PHP
This guide explains how to establish a connection between a PHP application and a MySQL database using the mysqli extension. It walks through the necessary setup, configuration, and execution of a simple SQL query.
Variables
Certain parameters must be provided to establish a successful connection to a MySQL database. Below is a breakdown of each required variable, its purpose, and where to find it. Here’s what each variable represents:
Variable |
Description |
Purpose |
---|---|---|
USER |
MySQL username, from the Elestio service overview page |
Identifies the database user who has permission to access the MySQL database. |
PASSWORD |
MySQL password, from the Elestio service overview page |
The authentication key is required for the specified USER to access the database. |
HOST |
Hostname for MySQL connection, from the Elestio service overview page |
The address of the server hosting the MySQL database. |
PORT |
Port for MySQL connection, from the Elestio service overview page |
The network port used to connect to MySQL. The default port is 3306. |
DATABASE |
Database Name for MySQL connection, from the Elestio service overview page |
The name of the database being accessed. A MySQL instance can contain multiple databases. |
These values can usually be found in the Elestio service overview details as shown in the image below, make sure to take a copy of these details and add it to the code moving ahead.
Prerequisites
- Install PHP
- Check if PHP is installed by running:
php -v
- If not installed, download it from php.net and install.
- Make sure the mysqli extension is enabled in your php.ini configuration.
- Check if PHP is installed by running:
Code
Once all prerequisites are set up, create a new file named mysql_connect.php
and add the following code:
<?php
$host = "HOST";
$user = "USER";
$password = "PASSWORD";
$database = "DATABASE";
$port = PORT;
// Create connection
$conn = new mysqli($host, $user, $password, $database, $port);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
echo "Connected to MySQL<br>";
// Run a test query to check the MySQL version
$result = $conn->query("SELECT VERSION()");
if ($result) {
$row = $result->fetch_assoc();
echo "MySQL Version: " . $row["VERSION()"];
$result->free();
} else {
echo "Query execution failed: " . $conn->error;
}
// Close connection
$conn->close();
?>
To execute the script, run the PHP server in the directory where mysql_connect.php
is located using:
php -S localhost:8000
Then, open a browser and go to:
http://localhost:8000/mysql_connect.php
If the connection is successful, the browser will display output similar to:
Connected to MySQL
MySQL Version: 8.0.36
Connecting with Go
This guide explains how to establish a connection between a Go application and a MySQL database using the go-sql-driver/mysql
package. It walks through the necessary setup, configuration, and execution of a simple SQL query.
Variables
Certain parameters must be provided to establish a successful connection to a MySQL database. Below is a breakdown of each required variable, its purpose, and where to find it. Here’s what each variable represents:
Variable |
Description |
Purpose |
---|---|---|
|
MySQL username, from the Elestio service overview page |
Identifies the database user who has permission to access the MySQL database. |
|
MySQL password, from the Elestio service overview page |
The authentication key is required for the specified USER to access the database. |
|
Hostname for MySQL connection, from the Elestio service overview page |
The address of the server hosting the MySQL database. |
|
Port for MySQL connection, from the Elestio service overview page |
The network port used to connect to MySQL. The default port is 3306. |
|
Database Name for MySQL connection, from the Elestio service overview page |
The name of the database being accessed. A MySQL instance can contain multiple databases. |
These values can usually be found in the Elestio service overview details, as shown in the image below. Make sure to take a copy of these details and add them to the code moving ahead.
Prerequisites
- Install Go
- Check if Go is installed by running:
go version
- If not installed, download it from golang.org and install.
- Check if Go is installed by running:
- Install the MySQL Driver
- Use the following command to install the go-sql-driver/mysql driver:
go get -u github.com/go-sql-driver/mysql
- Use the following command to install the go-sql-driver/mysql driver:
Code
Once all prerequisites are set up, create a new file named mysql_connect.go
and add the following code:
package main
import (
"database/sql"
"fmt"
"log"
_ "github.com/go-sql-driver/mysql"
)
func main() {
user := "USER"
password := "PASSWORD"
host := "HOST"
port := "PORT"
database := "DATABASE"
// Construct DSN (Data Source Name)
dsn := fmt.Sprintf("%s:%s@tcp(%s:%s)/%s", user, password, host, port, database)
// Open a connection
db, err := sql.Open("mysql", dsn)
if err != nil {
log.Fatalf("Connection failed: %v", err)
}
defer db.Close()
// Ping to verify connection
if err := db.Ping(); err != nil {
log.Fatalf("Ping failed: %v", err)
}
fmt.Println("Connected to MySQL")
// Run a test query to check the MySQL version
var version string
err = db.QueryRow("SELECT VERSION()").Scan(&version)
if err != nil {
log.Fatalf("Query execution failed: %v", err)
}
fmt.Printf("MySQL Version: %s\n", version)
}
To execute the script, open the terminal and navigate to the directory where mysql_connect.go
is located. Once in the correct directory, run the script with the commands:
go mod init example.com/mysqlconnect
go run mysql_connect.go
If the connection is successful, the terminal will display output similar to:
Connected to MySQL
MySQL Version: 8.0.36
Connecting with Java
This guide explains how to establish a connection between a Java application and a MySQL database using the mysql-connector-j
JDBC driver. It walks through the necessary setup, configuration, and execution of a simple SQL query.
Variables
Certain parameters must be provided to establish a successful connection to a MySQL database. Below is a breakdown of each required variable, its purpose, and where to find it. Here’s what each variable represents:
Variable |
Description |
Purpose |
---|---|---|
|
MySQL username, from the Elestio service overview page |
Identifies the database user who has permission to access the MySQL database. |
|
MySQL password, from the Elestio service overview page |
The authentication key is required for the specified USER to access the database. |
|
Hostname for MySQL connection, from the Elestio service overview page |
The address of the server hosting the MySQL database. |
|
Port for MySQL connection, from the Elestio service overview page |
The network port used to connect to MySQL. The default port is 3306. |
|
Database Name for MySQL connection, from the Elestio service overview page |
The name of the database being accessed. A MySQL instance can contain multiple databases. |
These values can usually be found in the Elestio service overview details as shown in the image below, make sure to take a copy of these details and add it to the code moving ahead.
Prerequisites
- Install Java
- Check if Java is installed by running:
java -version
. - If not installed, download it from oracle.com or install OpenJDK.
- Check if Java is installed by running:
- Install MySQL Connector/J
- Download the latest version
mysql-connector-j
from the official MySQL site.
- Download the latest version
Code
Once all prerequisites are set up, create a new file named MySQLConnect.java
and add the following code:
import java.sql.*;
import java.util.*;
public class MySQLConnect {
public static void main(String[] args) {
Map<String, String> config = new HashMap<>();
for (int i = 0; i < args.length - 1; i += 2)
config.put(args[i], args[i + 1]);
String url = String.format("jdbc:mysql://%s:%s/%s?useSSL=true",
config.get("-host"), config.get("-port"), config.get("-database"));
try {
Class.forName("com.mysql.cj.jdbc.Driver");
try (Connection conn = DriverManager.getConnection(url, config.get("-username"), config.get("-password"));
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("SELECT VERSION()")) {
System.out.println("Connected to MySQL");
if (rs.next()) System.out.println("MySQL Version: " + rs.getString(1));
}
} catch (Exception e) {
System.err.println("Connection error: " + e.getMessage());
}
}
}
To compile and run the Java program, use the following commands in your terminal:
javac MySQLConnect.java && java -cp mysql-connector-j-9.3.0.jar:. MySQLConnect -host HOST -port PORT -database DATABASE -username avnadmin -password PASSWORD
If the connection is successful, the terminal will display output similar to:
Connected to MySQL
MySQL Version: 8.0.41