Glossary
Recursive CTE (Common Table Expression)
A recursive CTE, or Common Table Expression, is a powerful tool in SQL programming that allows you to perform complex queries in a more efficient and organized manner. In essence, a CTE is a temporary result set that is defined within the execution of a single SQL statement. Recursive CTEs are a special type of CTE that allow for self-referential queries, meaning that they can reference themselves in the definition of the query.
This type of CTE is particularly useful in situations where you need to traverse hierarchical data, such as organizational charts or family trees. By using a recursive CTE, you can write a query that starts at the top level of the hierarchy and then traverses down through each level until it reaches the bottom. This allows you to easily retrieve all of the information you need without having to write multiple queries or use complex joins.
To create a recursive CTE, you first define the base case of the query, which is the starting point for the recursion. You then define a recursive case, which is the portion of the query that references the CTE itself. Finally, you combine the two cases into a single query using a UNION ALL statement.
By using a recursive CTE, you can greatly simplify your SQL code and make it more efficient and maintainable. However, it is important to use this tool responsibly and to always test your queries thoroughly to ensure that they are returning the correct results. With practice and experience, you can become a master of recursive CTEs and take your SQL programming to the next level.
A wide array of use-cases
Discover how we can help your data into your most valuable asset.
We help businesses boost revenue, save time, and make smarter decisions with Data and AI