Connect From Node.js App
Node.js developers can connect to MariaDB Cloud through a native MariaDB Connector. Using MariaDB Connector/Node.js you can connect to MariaDB Cloud to use and administer databases from within your Node.js application.
Install MariaDB Connector/Node.js
MariaDB Connector/Node.js is usually installed either from the Node.js repository or manually from the source code package.
Install MariaDB Connector/Node.js via Repository
To install MariaDB Connector/Node.js from the Node.js repository, use NPM:
npm install mariadb
NPM connects to the Node.js repository and downloads MariaDB Connector/Node.js and all relevant dependencies into the node_modules/
directory.
Install MariaDB Connector/Node.js via Source Code
To download and install the MariaDB Connector/Node.js manually from source code:
Go to the MariaDB Connectors download page:
In the "Product" dropdown, select the Node.js connector.
Click the "Download" button to download the source code package
When the source code package finishes downloading, install it with NPM:
$ npm install mariadb-connector-nodejs-*.tar.gz
NPM untars the download and installs MariaDB Connector/Node.js in the node_modules/
directory.
Connect with MariaDB Connector/Node.js (Callback API)
Node.js developers can use MariaDB Connector/Node.js to establish client connections with MariaDB Cloud.
Require Callback API
MariaDB Connector/Node.js provides two different connection implementations: one built on the Promise API and the other built on the Callback API.
To use the Callback API, use the following module:
const** mariadb = require**(**'mariadb/callback'**);
Connecting
createConnection(options) -> Connection
This is the base function used to create a Connection
object.
The createConnection(options)
function returns a Connection
object.
Determine the connection information for your MariaDB Cloud database service:
host
The fully Qualified Domain Name from the "Connect" window in MariaDB Cloud portal
port
The Read-Write Port or Read-Only Port from the "Connect" window in MariaDB Cloud portal
user
The desired username, which might be the default username in the Service Credentials view
password
The user's password, which might be the default password in the Service Credentials view if it was not yet customized
database
Database name to establish a connection to. No default is configured.
connectTimeout
Connection timeout in milliseconds. In Connector/Node.js 2.5.6, the default value changed to 1000. The default value for earlier versions is 10000.
rowsAsArray
A boolean value to indicate whether to return result sets as arrays instead of the default JSON. Arrays are comparatively faster.
Code Example: Connecting
The following code example connects using the database and user account created in the example setup:
const mariadb = require('mariadb/callback');
// Certificate Authority (CA)",
var serverCert = [fs.readFileSync(process.env.SKYSQL_CA_PEM, "utf8")];
// Declare async function
function main() {
let conn;
try {
conn = mariadb.createConnection({
host: "example.skysql.com",
port: 5009,
ssl: { ca: serverCert },
user: "db_user",
password: "db_user_password",
database: "test",
});
// Use Connection
// ...
} catch (err) {
// Manage Errors
console.log("SQL error in establishing a connection: ", err);
} finally {
// Close Connection
if (conn) conn.end(err => {if(err){
console.log("SQL error in closing a connection: ", err);}
});
}
}
main();
A
try...catch...finally
statement is used for exception handling.New connections are created in auto-commit mode by default.
When you are done with a connection, close it to free resources. Close the connection using the
connection.end([callback])
function.The script calls the
connection.end([callback])
function to close/end the connection in thefinally
block after the queries that are running have completed.The
end()
function takes a callback function that defines one implicit argument for theError
object if thrown in closing the connection as argument. If no error is generated in closing a connection theError
object isnull
.
Connecting With MariaDB Connector/Node.js (Promise API)
Node.js developers can use MariaDB Connector/Node.js to establish client connections with MariaDB Cloud.
Require Promise API
MariaDB Connector/Node.js provides two different connection implementations: one built on the Promise API and the other built on the Callback API. Promise is the default.
To use the Promise API, use the mariadb
module:
const** mariadb = require**(**'mariadb'**);
Connecting
createConnection(options) -> Promise
is the base function used to create a Connection
object.
The createConnection(options)
returns a Promise
that resolves to a Connection
object if no error occurs, and rejects with an Error
object if an error occurs.
Determine the connection information for your MariaDB Cloud database service:
host
The fully Qualified Domain Name from the "Connect" window in MariaDB Cloud portal
port
The Read-Write Port or Read-Only Port from the "Connect" window in MariaDB Cloud portal
user
The desired username, which might be the default username in the Service Credentials view
password
The user's password, which might be the default password in the Service Credentials view if it was not yet customized
database
Database name to establish a connection to. No default is configured.
connectTimeout
Connection timeout in milliseconds. In Connector/Node.js 2.5.6, the default value changed to 1000. The default value for earlier versions is 10000.
rowsAsArray
A boolean value to indicate whether to return result sets as arrays instead of the default JSON. Arrays are comparatively faster.
Create a file named .env
to store your database credentials:
# env 1
MDB_HOST = 192.0.2.50
MDB_PORT = 3306
MDB_USER = db_user
MDB_PASS = db_user_password
# env 2
MDB_HOST = example.skysql.com
MDB_PORT = 5001
MDB_CA_PEM = /path/to/skysql_chain.pem
MDB_USER = db_user
MDB_PASS = db_user_password
Code Example: Connecting
The following code example connects using the database and user account created in Setup for Examples:
// Required Modules
const fs = require("fs");
const mariadb = require("mariadb");
require("dotenv").config()
// Certificate Authority (CA)
const serverCert = [fs.readFileSync(process.env.MDB_CA_PEM, "utf8")];
// Declare async function
async function main() {
let conn;
try {
conn = await mariadb.createConnection({
host: process.env.MDB_HOST,
port: process.env.MDB_PORT,
user: process.env.MDB_USER,
password: process.env.MDB_PASS,
ssl: { ca: serverCert },
database: "test",
});
// Use Connection
// ...
} catch (err) {
// Manage Errors
console.log("SQL error in establishing a connection: ", err);
} finally {
// Close Connection
if (conn) conn.close();
}
}
main();
Load the
mariadb
module using therequire()
function.Declare an async function called
main()
using theasync
keyword.An async function provides asynchronous, Promise-based code behavior.
Async functions may declare
await
expressions using theawait
keyword.Await expressions yield control to a promise-based asynchronous operation.
Await expressions resume control after the awaited operation is either fulfilled or rejected.
The return value of an
await
expression is the resolved value of thePromise
.The async function name
main
is arbitrary and does not have special meaning as in some other programming languages.Declare a variable called
conn
for the connection to be created using alet
statement with the async functionmain
.A
try...catch...finally
statement is used for exception handling.New connections are by default created in auto-commit mode.
In the
try
block, create a new connection using themariadb#createConnection(options)
function in the Promise API.Send error messages if any to the console in the
catch
block.When you are done with a connection, close it to free resources. Close the connection using the
close()
function.
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