Tutorials Programming Tutorials, Guides & Best Practices

Window functions calculate values across a set of rows related to the current row without collapsing rows into groups.

• ROW_NUMBER(): Assigns unique sequential numbers.
• RANK(): Assigns ranks with gaps on ties.
• DENSE_RANK(): Ranks without gaps.
• NTILE(n): Divides rows into n groups.
• LEAD() / LAG(): Accesses next/previous rows.

In this tutorial, we will explore various types of SQL joins, understand their syntax, and learn through examples. By the end of this guide, you will have a solid understanding of how to use joins to fetch related data across tables efficiently.

In a relational database, data is organized in tables. Each table consists of rows and columns, with each row representing a unique record. Tables can be related to each other through keys, typically primary and foreign keys. Joins allow us to combine rows from two or more tables based on a related column between them.