Rank and Row

When analyzing sales data, we might want to find the top 3 best-selling products in each category or determine who placed the earliest order among all customers. These kinds of questions require more than just filtering or grouping; we need to assign positions or row numbers to our data based on a sorting rule.

This is where the Rank and row pattern becomes essential.

In this lesson, we’ll learn how to rank rows, assign row numbers, and manage ties. We'll explore common use cases, understand the structure of ranking functions, and work with examples from our course database. By the end, we’ll be comfortable with SQL's ranking tools and know when and how to use them effectively.

In this lesson, we will:

• Understand the purpose and structure of ranking functions in SQL.

• Learn how to assign ranks and row numbers to ordered data.

• Practice using RANK(), DENSE_RANK(), and ROW_NUMBER().

• Solve common ranking problems using real-world data.

Pattern overview

Category:

• Sequencing & Hierarchical Patterns

Intent:

To assign a position to each row based on a specific order, optionally grouped by categories.

Motivation:

There are many real-world scenarios where we need to identify the first, top, or ranked items in a dataset. For example:

• What are the top 3 best-selling products per category?

• Which orders were placed first by each customer?

• Who are the top 5 VIP customers by loyalty points?

SQL’s ranking functions allow us to answer these questions cleanly without subqueries or procedural loops.

Also known as:

• Ranking Functions

• Row Numbering

• Top-N per Group

Structure