Do you want to query complex data structures in an iterative way? Do you have access to hierarchical data structures that need to be queried? This course will teach you the tools required to solve these questions. You will learn how to write recursive queries and query hierarchical data structures. To do this, you will use Common Table Expressions (CTE) and the recursion principle on a wide variety of datasets. You will, for example, dig into a flight plan dataset and learn how to find the best and cheapest connection between two airports. After completing this course, you will understand the principle of recursion, and be able to identify and create hierarchical data models.
Recursion and Common Table Expression (CTE)Free
In this chapter, you will learn about recursion and why it is beneficial to apply this technique. You will also refresh your knowledge about Common Expression Tables (CTE).
Hierarchical and Recursive Queries
In this chapter, you will learn about recursive CTEs, how to query hierarchical datasets, and finally, how to apply recursive CTEs on hierarchical data.
Creating Data Models on Your Own
In this chapter, you will learn how to create and modify database tables. You will learn about relational and hierarchical data models, how they differ, and when each model should be used.
Hierarchical Queries of Real-World Examples
In this chapter, you will practice your learnings about hierarchical and recursive querying on real-world problems, such as finding possible flight routes, assembling a car, and modeling a power grid.
Data Engineering Enthusiast
Dominik Egarter is IT architecture manager & data engineering enthusiast at Kelag, a power utility company in Austria. He is responsible for the data and information architecture and leads several data science and data engineering projects in the fields of predictive maintenance, telecommunication networks, power grid networks, and customer insights. Dominik regularly uses R and SQL to implement algorithms and apps (R Shiny apps) which could be used to enforce new business insights and makes data easy to use for everyone.