How To Efficiently Assign A Database Temporary Ranking Of Values To Rows via DENSE_RANK()

Description: This application is an example of assigning a database temporary ranking of values to rows via the window function, DENSE_RANK(). In comparison with the RANK() window function, DENSE_RANK() avoid gaps within partition. This window function is available in almost all databases, and starting with version 8.x is available in MySQL as well.

Key points:

• commonly, you don't need to fetch in the result set the temporary ranking of values produced by DENSE_RANK() (you will use it internally, in the query, usually in the WHERE clause and CTEs), but, this time, let's write a Spring projection (DTO) that contains a getter for the column generated by DENSE_RANK() as well
• write several native querys relying on DENSE_RANK() window function

Output sample:

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