Node.js can be used in database applications.
One of the most popular databases is MySQL.
MySQL Database
To be able to experiment with the code examples, you should have MySQL installed on your computer.
You can download a free MySQL database at https://www.mysql.com/downloads/.
Install MySQL Driver
Once you have MySQL up and running on your computer, you can access it by using Node.js.
To access a MySQL database with Node.js, you need a MySQL driver. This tutorial will use the “mysql” module, downloaded from NPM.
To download and install the “mysql” module, open the Command Terminal and execute the following:
C:UsersYour Name>npm install mysql
Now you have downloaded and installed a mysql database driver.
Node.js can use this module to manipulate the MySQL database:
var mysql = require(‘mysql’);
Create Connection
Start by creating a connection to the database.
Use the username and password from your MySQL database.
demo_db_connection.js
var mysql = require(‘mysql’);
var con = mysql.createConnection({
host: “localhost”,
user: “yourusername“,
password: “yourpassword“
});
con.connect(function(err) {
if (err) throw err;
console.log(“Connected!”);
});
Run example »
Save the code above in a file called “demo_db_connection.js” and run the file:
Run “demo_db_connection.js”
C:UsersYour Name>node demo_db_connection.js
Which will give you this result:
Connected!
Now you can start querying the database using SQL statements.
Query a Database
Use SQL statements to read from (or write to) a MySQL database. This is also called “to query” the database.
The connection object created in the example above, has a method for querying the database:
con.connect(function(err) {
if (err) throw err;
console.log(“Connected!”);
con.query(sql, function (err, result) {
if (err) throw err;
console.log(“Result: ” + result);
});
});
The query method takes an sql statements as a parameter and returns the result.
Learn how to read, write, delete, and update a database in the next chapters.
Read more about SQL statements in our SQL Tutorial.
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