Create Table

CREATE TABLE command is used to create a table in MySQL. You must make it sure that you define the name of the database when you create the connection.

Example

For creating a table named "employees".

Create a js file named employees.js having the following data in DBexample folder.

snippet
var mysql = require('mysql');
var con = mysql.createConnection({
host: "localhost",
user: "root",
password: "12345",
database: "javatpoint"
});
con.connect(function(err) {
if (err) throw err;
console.log("Connected!");
var sql = "CREATE TABLE employees (id INT, name VARCHAR(255), age INT(3), city VARCHAR(255))";
con.query(sql, function (err, result) {
if (err) throw err;
console.log("Table created");
});
});

Now open command terminal and run the following command:

snippet
Node employees.js
Node.js create table 1

Verification

To verify if the table is created or not, use the SHOW TABLES command.

Node.js create table 2

You can also check the structure of the table using DESC command:

Node.js create table 3

Create Table Having a Primary Key

Create Primary Key in New Table:

Let's create a new table named "employee2" having id as primary key.

Create a js file named employee2.js having the following data in DBexample folder.

snippet
var mysql = require('mysql');
var con = mysql.createConnection({
host: "localhost",
user: "root",
password: "12345",
database: "javatpoint"
});
con.connect(function(err) {
if (err) throw err;
console.log("Connected!");
var sql = "CREATE TABLE employee2 (id INT PRIMARY KEY, name VARCHAR(255), age INT(3), city VARCHAR(255))";
con.query(sql, function (err, result) {
if (err) throw err;
console.log("Table created");
});
});

Now open command terminal and run the following command:

snippet
Node employee2.js
Node.js create table 4

Verification

To verify if the table is created or not, use the SHOW TABLES command.

Node.js create table 5

You can also check the structure of the table using DESC command to see that id is a primary key :

Node.js create table 6

Add columns in existing Table:

ALTER TABLE statement is used to add a column in an existing table. Take the already created table "employee2" and use a new column salary.

Replace the data of the "employee2" table with the following data:

snippet
var mysql = require('mysql');
var con = mysql.createConnection({
host: "localhost",
user: "root",
password: "12345",
database: "javatpoint"
});
con.connect(function(err) {
if (err) throw err;
console.log("Connected!");
var sql = "ALTER TABLE employee2 ADD COLUMN salary INT(10)";
con.query(sql, function (err, result) {
if (err) throw err;
console.log("Table altered");
});
});

Now open command terminal and run the following command:

snippet
Node employee2.js
Node.js create table 7

Verification

Node.js create table 8

A new column salary is created in the table employee2.

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