Pseudo Code Generator | JavaScript

Top Customers Retrieval Function

This function fetches the top five customers based on total spending from existing data in customers and orders tables, returning a table with their first name, last name, and total amount spent.

Prompt

CREATE OR REPLACE FUNCTION GetTopCustomers()
RETURNS TABLE (first_name VARCHAR, last_name VARCHAR, total_spent DECIMAL) AS $$
BEGIN
    RETURN QUERY
    SELECT 
        c.first_name, 
        c.last_name, 
        SUM(o.total_amount) AS total_spent
    FROM 
        customers c
    JOIN 
        orders o ON c.customer_id = o.customer_id
    GROUP BY 
        c.first_name, c.last_name
    ORDER BY 
        total_spent DESC
    LIMIT 5;
END;
$$ LANGUAGE plpgsql;

Answer

Pseudo Code for GetTopCustomers Function

Purpose

This function retrieves the top five customers based on the total amount spent on orders.

Inputs

None (the function operates on existing data in the customers and orders tables)

Outputs

A table containing:
- first_name: String of the customer's first name
- last_name: String of the customer's last name
- total_spent: Decimal value representing the total amount spent by the customer

Pseudo Code Structure

FUNCTION GetTopCustomers() RETURNS TABLE (first_name, last_name, total_spent)

    // Initialize result table
    INITIALIZE result_table AS TABLE (first_name VARCHAR, last_name VARCHAR, total_spent DECIMAL)

    // Query to retrieve top customers based on total spending
    result_set = EXECUTE QUERY
        SELECT 
            customers.first_name, 
            customers.last_name, 
            SUM(orders.total_amount) AS total_spent
        FROM 
            customers
        JOIN 
            orders ON customers.customer_id = orders.customer_id
        GROUP BY 
            customers.first_name, customers.last_name
        ORDER BY 
            total_spent DESC
        LIMIT 5

    // Populate result table with the result set
    FOR EACH record IN result_set DO
        ADD record TO result_table

    // Return the result table
    RETURN result_table

END FUNCTION

Explanation of Logic

Define a function GetTopCustomers that returns a table with three columns.
Initialize a result table to hold the output data.
Execute a SQL query that performs the following:
- Selects the first and last names of customers along with the sum of their total amounts from orders.
- Joins the customers and orders tables using customer_id.
- Groups the results by customer names to aggregate the total spent.
- Orders the results in descending order based on the total spent amount.
- Limits the results to the top five customers.
Loop through each record in the result set and add it to the initialized result table.
Return the populated result table.

This pseudo code is designed for clarity and ease of understanding, effectively summarizing the logic and operations of the original SQL function while remaining devoid of complex programming syntax.

Description

This function fetches the top five customers based on total spending from existing data in customers and orders tables, returning a table with their first name, last name, and total amount spent.