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

 dans Sites anglophones  étiqueté #sql interview questions / Advanced SQL / Data / Database / Date Calculations / Date computation / DATEDIFF / LAG / LAG function / LEAD / OVER() / Performance / Performance and Tuning / Performance Tuning / Programming Language / SQL / SQL Compare / sql monitor / SQL Performance / SQL Prompt / SQL Script / SQL Server / t-sql / time series / TSQL / Window Functions par

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