How to use the ROW_NUMBER() Window Function In SQL

As, we’ve already discussed that, in SQLite, there are two primary methods are widely used for Pagination, i.e. ‘LIMIT‘ and ‘OFFSET‘ clauses; let’s now move to another important concept in Pagination, i.e. “ROW_NUMBER()” Window Function. To understand this concept clearly, we’ll go through an example so that we get hand-on knowledge of the concept.

Syntax:

SELECT 
    ROW_NUMBER() OVER (ORDER BY column_name) AS row_num,
    * 
FROM table_name
LIMIT number_of_rows OFFSET starting_row;

Here, we need to replace “column_name” with the original column name of my ‘employee‘ table. So, the column name to replace is “employee_id“.

Example 1: Pagination with ROW_NUMBER()

-- Retrieve the first 5 entries using ROW_NUMBER() window function

SELECT 
    ROW_NUMBER() OVER (ORDER BY employee_id) AS row_num,
    * 
FROM employees
LIMIT 5;

Output:

Explanation: In this example, we have used the “ROW_NUMBER()” window function. This function helps to assign a unique number to each row based on a specified order. I also used the “ORDER BY” clause here and it’s helping to specify a specific order for “ROW_NUMBER()” function, i.e. ORDER BY “employee_id“.

This query should fetch the first 5 entries with thier corresplonding row numbers. And that’s what we got as our output.

Pagination is a common requirement in database applications, especially when dealing with large datasets. SQLite, a popular embedded relational database management system, offers several methods to paginate results efficiently. In this article, we will learn about what is the best way for efficient paging by understanding various methods along with the syntax and examples.