Why date handling is essential in MySQL - See It in Action

Why Date Handling Is Essential in MySQL

📖 Scenario: You are managing a small online store database. You need to keep track of when orders are placed and delivered.

🎯 Goal: Build a simple MySQL table to store order dates and learn why handling dates correctly is important.

📋 What You'll Learn

Create a table named orders with columns order_id (integer), order_date (date), and delivery_date (date).

Add a configuration variable to set a delivery threshold date.

Write a query to find orders delivered after the threshold date.

Add a final query to count how many orders were delivered late.

💡 Why This Matters

🌍 Real World

Tracking order and delivery dates is common in online stores, logistics, and many business systems.

💼 Career

Database professionals often write queries involving dates to generate reports, monitor deadlines, and ensure timely operations.

1

Create the orders table

Write a MySQL statement to create a table called orders with three columns: order_id as an integer, order_date as a DATE type, and delivery_date as a DATE type.

MySQL

-- Your code here to create the orders table

Need a hint?

Use CREATE TABLE with column names and types exactly as specified.

2

Set a delivery threshold date

Create a MySQL variable called @delivery_threshold and set it to the date '2024-01-01'.

MySQL

CREATE TABLE orders (
  order_id INT,
  order_date DATE,
  delivery_date DATE
);
-- Your code here to set @delivery_threshold

Need a hint?

Use SET to assign the date string to the variable.

3

Query orders delivered after the threshold

Write a SELECT query to get all columns from orders where delivery_date is greater than the variable @delivery_threshold.

MySQL

CREATE TABLE orders (
  order_id INT,
  order_date DATE,
  delivery_date DATE
);

SET @delivery_threshold = '2024-01-01';
-- Your code here to select orders delivered after @delivery_threshold

Need a hint?

Use a WHERE clause comparing delivery_date to @delivery_threshold.

4

Count late deliveries

Write a SELECT query to count the number of orders where delivery_date is after @delivery_threshold. Name the count column late_deliveries.

MySQL

CREATE TABLE orders (
  order_id INT,
  order_date DATE,
  delivery_date DATE
);

SET @delivery_threshold = '2024-01-01';

SELECT * FROM orders WHERE delivery_date > @delivery_threshold;
-- Your code here to count late deliveries

Need a hint?

Use COUNT(*) with an alias and the same WHERE condition.