Creating Table in MySQL

We can create a table in a database using the CREATE TABLE query in MySQL. Let's create a simple table "Employees", consisting of five columns: "employeeID", "firstname", "lastname", "email" and "joining_date". 

The query will look something like this:

CREATE TABLE Employees(
employeeID INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
firstname VARCHAR(30) NOT NULL,
lastname VARCHAR(30) NOT NULL,
email VARCHAR(50),
joining_date TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
)

Let's break down the attributes:

• NOT NULL - Each row must contain a value for that column, null values are not allowed.
• DEFAULT value - Set a default value that is added when no other value is passed.
• UNSIGNED - Used for number types. It limits the stored data to positive numbers and zero.
• AUTO INCREMENT - MySQL automatically increases the value of the field by 1 each time a new record is added.
• PRIMARY KEY - Used to uniquely identify the rows in a table.

 

This is how it will look in a PHP script:

<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "cwhDB";

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
  die("Connection failed: " . $conn->connect_error);
}

// sql to create table
$sql = "CREATE TABLE Employees(
employeeID INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
firstname VARCHAR(30) NOT NULL,
lastname VARCHAR(30) NOT NULL,
email VARCHAR(50),
joining_date TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
)";

if ($conn->query($sql) === TRUE) {
  echo "Table Employees created successfully";
} else {
  echo "Error creating table: " . $conn->error;
}

$conn->close();
?>