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How to create a table in MySQL using NodeJS

FOLASAYO SAMUEL OLAYEMI's photo
FOLASAYO SAMUEL OLAYEMI
·Apr 15, 2022·

2 min read

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Table of contents

  • Primary Key

To create a table in MySQL, use the "CREATE TABLE" statement.

Note: Make sure you define the name of the database when you create the connection.

Code Sample:

const mysql = require('mysql');

const con = mysql.createConnection({
  host: "localhost",
  user: "yourusername",
  password: "yourpassword",
  database: "mydb"
});

con.connect(function(err) {
  if (err) throw err;
  console.log("Connected!");
  const sql = "CREATE TABLE customers (name VARCHAR(255), address VARCHAR(255))";
  con.query(sql, function (err, result) {
    if (err) throw err;
    console.log("Table created");
  });
});

Now, save the code above in a file called "demo_create_table.js" and run the file on your terminal:

node demo_create_table.js

This will give you this result:

Connected!
Table created

Primary Key

When creating a table, you should also create a column with a unique key for each record.

This can be done by defining a column as "INT AUTO_INCREMENT PRIMARY KEY" which will insert a unique number for each record. Starting at 1, and increased by one for each record.

Now, create primary key when creating the table:

const mysql = require('mysql');

const con = mysql.createConnection({
  host: "localhost",
  user: "yourusername",
  password: "yourpassword",
  database: "mydb"
});

con.connect(function(err) {
  if (err) throw err;
  console.log("Connected!");
  const sql = "CREATE TABLE customers (id INT AUTO_INCREMENT PRIMARY KEY, name VARCHAR(255), address VARCHAR(255))";
  con.query(sql, function (err, result) {
    if (err) throw err;
    console.log("Table created");
  });
});

Note: If the table already exists, use the ALTER TABLE keyword:

Now, create primary key on an existing table:

const mysql = require('mysql');

const con = mysql.createConnection({
  host: "localhost",
  user: "yourusername",
  password: "yourpassword",
  database: "mydb"
});

con.connect(function(err) {
  if (err) throw err;
  console.log("Connected!");
  const sql = "ALTER TABLE customers ADD COLUMN id INT AUTO_INCREMENT PRIMARY KEY";
  con.query(sql, function (err, result) {
    if (err) throw err;
    console.log("Table altered");
  });
});

Thanks for reading...

Happy Coding!

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