SQL Window Functions Series: LAG() and LEAD()

In the realm of data analysis, being able to understand the relationships between sequential data points is paramount. Whether you’re analyzing sales trends, monitoring server performance, or studying user engagement, there will inevitably come a time when you need to compare a data point with its predecessor or successor. This is where SQL window functions shine, particularly LAG() and LEAD().

In our previous article, we unraveled the intricacies of RANK() and DENSE_RANK(), showcasing their power in assigning rankings within a dataset. Continuing our journey through window functions, today’s focus shifts to LAG() and LEAD(). These functions, while seemingly simple, provide