SQL

Querying MS SQL (FLO)

Querying MS SQL using FLO's Dataset

Dataset Story
The dataset consists of the information obtained from the past shopping behaviors of customers who made their last purchases from FLO as OmniChannel (both online and offline shopper) in 2020-2021.

Variables

master_id: Customer ID
order_channel: Shopping platform (Android, ios, Desktop, Mobile, Offline)
last_order_channel: The channel where the most recent purchase was made
first_order_date: Customer's first order date
last_order_date: Customer's last order date
last_order_date_online: Customer's last offline order date
last_order_date_offline: Customer's last online order date
order_num_total_ever_online: The total number of orders made by the customer online
order_num_total_ever_offline: The total number of orders made by the customer offline
customer_value_total_ever_offline: The total price paid by the customer for offline orders
customer_value_total_ever_online: The total price paid by the customer for online orders
interested_in_categories_12: List of categories the customer has shopped in the last 12 months

Task 1:

Create a table named FLO to include variables from a database named 'Customers' and the given dataset.

Solution:

Creating Database:
```
CREATE DATABASE CUSTOMERS;
```
Importing Dataset:

Click to enlarge image

Retrieve all rows and columns from the 'FLO' table.
```
SELECT *
FROM FLO;
```
Click to enlarge image

Task 2:

Write a query to show the number of distinct customers who made purchases.

Solution:

SELECT
    COUNT(DISTINCT master_id) AS TOTAL_CUSTOMER
FROM FLO;

Task 3:

Write a query to retrieve the total number of transactions and revenue.

Solution:

SELECT
    SUM(order_num_total_ever_online + order_num_total_ever_offline) AS TOTAL_TRANSACTION,
    SUM(customer_value_total_ever_online + customer_value_total_ever_offline) AS TOTAL_REVENUE
FROM FLO;

Task 4:

Write a query to calculate the average revenue per transaction.

Solution:

SELECT
    (SUM(customer_value_total_ever_online + customer_value_total_ever_offline) /
    SUM(order_num_total_ever_online + order_num_total_ever_offline)) AS AVG_REVENUE_PER_TRANSACTION
FROM FLO;

Task 5:

Write a query to retrieve the total revenue and number of transactions for purchases made through the last order channel ('last_order_channel').

Solution:

SELECT
    last_order_channel AS LAST_ORDER_CHANNEL,
    SUM(order_num_total_ever_online + order_num_total_ever_offline) AS TOTAL_TRANSACTION,
    SUM(customer_value_total_ever_online + customer_value_total_ever_offline) AS TOTAL_REVENUE
FROM FLO
GROUP BY last_order_channel
ORDER BY TOTAL_REVENUE DESC;

Task 6:

Write a query to retrieve the total revenue obtained in the breakdown of 'store_type'.

Solution:

SELECT
    store_type AS STORE_TYPE,
    SUM(customer_value_total_ever_online + customer_value_total_ever_offline) AS TOTAL_REVENUE
FROM FLO
GROUP BY store_type
ORDER BY TOTAL_REVENUE DESC;

Task 7:

Write a query to retrieve the number of transactions breakdown by year (Consider the customer's first order date ('first_order_date') year).

Solution:

SELECT
    DATEPART(YEAR, first_order_date) AS YEAR_,
    SUM(order_num_total_ever_online + order_num_total_ever_offline) AS TOTAL_TRANSACTION
FROM FLO
GROUP BY DATEPART(YEAR, first_order_date)
ORDER BY YEAR_ DESC;

Task 8:

Write a query to calculate the average revenue per transaction based on the last order channel breakdown.

Solution:

SELECT
    last_order_channel AS LAST_ORDER_CHANNEL,
    (SUM(customer_value_total_ever_online + customer_value_total_ever_offline) /
    SUM(order_num_total_ever_online + order_num_total_ever_offline)) AS AVG_REVENUE_PER_TRANSACTION
FROM FLO
GROUP BY last_order_channel
ORDER BY AVG_REVENUE_PER_TRANSACTION DESC;

Task 9:

Write a query to find the most popular category in the last 12 months.

Solution:

SELECT
    interested_in_categories_12 AS LAST_12_MONTH_CATEGORIES,
    COUNT(*) AS CATEGORY_COUNT
FROM FLO
GROUP BY interested_in_categories_12;

Task 10:

Write a query to find the most preferred 'store_type' information.

Solution:

SELECT TOP 1
    store_type AS STORE_TYPE,
    COUNT(*) AS STORE_TYPE_COUNT
FROM FLO
GROUP BY store_type;

Task 11:

Write a query to find the most popular category and the total amount spent in this category based on the last order channel ('last_order_channel').

Solution:

SELECT
    DISTINCT last_order_channel AS LAST_ORDER_CHANNEL,
    (SELECT TOP 1
        interested_in_categories_12
    FROM FLO
    WHERE last_order_channel=f.last_order_channel
    GROUP BY interested_in_categories_12
    ORDER BY SUM(order_num_total_ever_online + order_num_total_ever_offline) DESC
    ) AS POPULAR_CATEGORIES,
    (SELECT TOP 1
        SUM(order_num_total_ever_online + order_num_total_ever_offline)
    FROM FLO
    WHERE last_order_channel=f.last_order_channel
    GROUP BY interested_in_categories_12
    ORDER BY SUM (order_num_total_ever_online + order_num_total_ever_offline) DESC
    ) AS TOTAL_TRANSACTION
FROM FLO f;

Task 12:

Write a query to retrieve the ID of the person who made the most purchases.

Solution:

SELECT TOP 1
    master_id AS CUSTOMER_ID,
    SUM(order_num_total_ever_online + order_num_total_ever_offline) AS TOTAL_TRANSACTION
FROM FLO
GROUP BY master_id
ORDER BY TOTAL_TRANSACTION DESC;

Task 13:

Write a query to retrieve the average revenue per transaction and the average shopping day frequency (shopping frequency) of the person who made the most purchases.

Solution:

SELECT TOP 1
    master_id AS CUSTOMER_ID,
    (SUM(customer_value_total_ever_online + customer_value_total_ever_offline) /
    SUM(order_num_total_ever_online + order_num_total_ever_offline)) AS AVG_REVENUE_PER_TRANSACTION,
    DATEDIFF(DAY, first_order_date, last_order_date) / (SUM(order_num_total_ever_online + order_num_total_ever_offline)) AS AVG_SHOPPING_DAY_FREQUENCY
FROM FLO
GROUP BY master_id, first_order_date, last_order_date
ORDER BY SUM(order_num_total_ever_online + order_num_total_ever_offline) DESC;

Task 14:

Write a query to retrieve the customer who made the most purchases based on the last order channel ('last_order_channel') breakdown.

Solution:

SELECT DISTINCT last_order_channel AS LAST_ORDER_CHANNEL,
    (SELECT TOP 1
        master_id
    FROM FLO
    WHERE last_order_channel=f.last_order_channel
    GROUP BY master_id
    ORDER BY SUM(customer_value_total_ever_online + customer_value_total_ever_offline) DESC
    ) AS CUSTOMER_ID,

    (SELECT TOP 1
        SUM(customer_value_total_ever_online + customer_value_total_ever_offline)
    FROM FLO
    WHERE last_order_channel=f.last_order_channel
    GROUP BY master_id
    ORDER BY SUM(customer_value_total_ever_online + customer_value_total_ever_offline) DESC
    ) AS TOTAL_REVENUE
FROM FLO f;

Task 15:

Write a query to retrieve the ID of the person who made the most recent purchase (There are multiple IDs making purchases on the maximum date; include all).

Solution:

SELECT
    master_id CUSTOMER_ID,
    last_order_date LAST_ORDER_DATE
FROM FLO
WHERE last_order_date = (SELECT MAX(last_order_date)FROM FLO);