A Temporary Table in SQL Server

We may want to use a temporary table in SQL when you need to store intermediate results of a complex query or when you want to manipulate and transform data before using it in subsequent queries. 

Common Scenarios:

Large datasets — Multiple queries — Data transformation — Performance optimization

Example:

Suppose you need to answer the next requirements:

1. Calculate the total revenue generated by each product for the current year.

2. Calculate the average revenue generated by each product for the previous year.

3. Identify the products that had a higher revenue growth rate in the current year compared to the previous year.

Solution:

The idea with the temporary table will be to return the product ID, total revenue, average revenue, and growth rate for each product that generated more revenue in the current year compared to the previous year.

1. Create a temporary table to store the revenue generated by each product for the current year:

2. Create a temporary table to store the average revenue generated by each product for the previous year: 

3. Join the two temporary tables to calculate the revenue growth rate for each product: