Get the Average Order Value for Each Product Category Query Using MS SQL Server?

To get the average order value for each product category using Microsoft SQL Server, you need to join the relevant tables, aggregate the order values by category, and then compute the average.

Assuming you have the following tables:

• Orders table with columns OrderID and OrderAmount.
• OrderItems table with columns OrderID, ProductID, and Quantity.
• Products table with columns ProductID, CategoryID, and ProductName.
• Categories table with columns CategoryID and CategoryName.

Here’s a step-by-step SQL query to achieve this:

SQL Query

-- Query to get the average order value for each product category

WITH OrderDetails AS (

    SELECT

        o.OrderID,

        SUM(oi.Quantity * p.Price) AS OrderValue

    FROM

        Orders o

        JOIN OrderItems oi ON o.OrderID = oi.OrderID

        JOIN Products p ON oi.ProductID = p.ProductID

    GROUP BY

        o.OrderID

),

CategoryOrderValues AS (

    SELECT

        p.CategoryID,

        AVG(od.OrderValue) AS AverageOrderValue

    FROM

        OrderDetails od

        JOIN Products p ON od.ProductID = p.ProductID

    GROUP BY

        p.CategoryID

)

SELECT

    c.CategoryID,

    c.CategoryName,

    cov.AverageOrderValue

FROM

    CategoryOrderValues cov

    JOIN Categories c ON cov.CategoryID = c.CategoryID

ORDER BY

    cov.AverageOrderValue DESC;

Explanation

1. OrderDetails CTE:

   • Calculates the total value of each order by joining the Orders, OrderItems, and Products tables.
   • SUM(oi.Quantity * p.Price) AS OrderValue: Computes the total value for each order based on the quantity of each product and its price.
   • GROUP BY o.OrderID: Groups by OrderID to get the total order value for each order.

2. CategoryOrderValues CTE:

   • Computes the average order value for each product category.
   • AVG(od.OrderValue) AS AverageOrderValue: Calculates the average order value by category.
   • GROUP BY p.CategoryID: Groups by CategoryID to get the average order value for each category.

3. Main Query:

   • JOIN Categories c ON cov.CategoryID = c.CategoryID: Joins with the Categories table to get category names.
   • ORDER BY cov.AverageOrderValue DESC: Orders the results by average order value in descending order.

Additional Considerations

• Price Column: Ensure the Products table has a Price column. If the price is stored differently or in another table, adjust the query accordingly.
• Missing Data: Ensure there are no missing or incorrect price or quantity values that could affect the calculations.
• Performance: Indexes on OrderID, ProductID, and CategoryID can help improve query performance.

Adjust the column names and table structure based on your actual schema. This query provides a clear method for calculating and retrieving the average order value for each product category.