Creating a Table
To create a table in MySQL, use the "CREATE TABLE" statement.
Make sure you define the name of the database when you create the connection:
Example
Create a table named "customers":
let mysql = require('mysql');
let con = mysql.createConnection({
host: "localhost", user: " yourusername ", password: " yourpassword ",
database: "mydb"
});
con.connect(function(err) {
if (err) throw err;
console.log("Connected!");
let sql = " CREATE TABLE customers (name VARCHAR(255), address VARCHAR(255) )";
con.query(sql, function (err, result) {
if (err)
throw err;
console.log("Table created");
});
});Save the code above in a file called "demo_create_table.js" and run the file:
Run "demo_create_table.js"
C:\Users\
Your Name
>node demo_create_table.jsWhich will give you this result
Connected! Table createdPrimary 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.
Example
Create primary key when creating the table:
let mysql = require('mysql');
let con = mysql.createConnection({
host: "localhost", user: " yourusername ", password: " yourpassword ",
database: "mydb"
});
con.connect(function(err) {
if (err) throw err;
console.log("Connected!");
let 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");
});
});If the table already exists, use the ALTER TABLE keyword:
Example
Create primary key on an existing table:
let mysql = require('mysql');
let con = mysql.createConnection({
host: "localhost", user: " yourusername ", password: " yourpassword ",
database: "mydb"
});
con.connect(function(err) {
if (err) throw err;
console.log("Connected!");
let 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");
});
});