Working with Self-Joins in SQL Self-joins can be a bit tricky to understand at first, but they are incredibly powerful when you need to compare rows within the same table. Here’s a simple way to understand and use self-joins: A self-join is a regular join, but the table is joined with itself. Use Cases: - Comparing Rows: Compare rows within the same table. - Hierarchical Data: Query hierarchical data, such as organizational charts or family trees. Self-joins can be powerful tools for analyzing relationships within the same table. Experiment with self-joins to see how they can help you query your data more effectively. Here is a code snippet to help you understand how `Self-Join` works: 👇 Found this helpful? Repost it! 🔁 Follow Akash AB for Practical Data Engineering #sql #datascience #dataengineering #dataanalytics #selfjoin
Question on why use JOIN verse LEFT JOIN in this situation. Is the assumption that all employees rows have a valid manager_id? Because if they don't those rows will be removed from the view.
I read the caption and thought there may be a another example/query on SELF JOIN. but everytime the same question, employee and manager table😍
Solid — understanding self-joins really improves how you think about relationships in data.
Great explanation. Self-joins confuse a lot of learners at first, but once you see them as “comparing a table to itself,” they become much easier to use. Especially useful for hierarchies, manager-employee mapping, and row-to-row comparisons
Thanks for sharing!
Great share
Great share
Thanks for sharing
Helpful
This becomes a lot easier to understand if you alias one copy as employee and the other as manager. At that point, the problem becomes, “how can I merge or stitch these two copies of the same table together in such a way that the employee and corresponding manager’s information is represented within a single row.”