Gain new skills and advance your career with this free Advanced SQL course from Oracle. Earn a free certificate of completion.
Oracle Advanced SQL course description
This course continues where Databases for Developers: Foundations left off, taking you further on your SQL journey. The class consists of a series of videos introducing concepts, interactive coding sections, and quizzes to test your understanding.
In this free Oracle Advanced SQL course, you’ll learn:
- Null: Null is a placeholder for missing or not applicable information. But it introduces a third state to true/false logic: unknown. This module shows you the correct way to query null values.
- Subqueries: A subquery is a query buried in another SQL statement. These come in several varieties. This module explains their differences and how to use them.
- Order By and Top-N: To guarantee your results are sorted in a particular way, you must use an order by clause. This module shows you how this works. It goes on to explain how to filter results to show the first N rows of a sorted data set.
- Analytic functions: Aggregate functions summarize data, so you get one row per group. But sometimes you need to see the individual rows in the group alongside the totals. To do this you need analytic functions. But that’s not all. Analytic functions enable you to define sliding windows over your rows. So you can compute running totals with ease. This module gives an overview of how to do this.
- Pivot and Unpivot: Sometimes you need to summarize data by week or month. But with the dates as columns instead of rows! So you need to convert the row values into column headings. Or the reverse. This module shows you how to do this with the pivot and unpivot clauses.
- Union, Minus and Intersect: You can combine rows from two tables to get all the rows, only those in common or those in one table not in the other. This module shows you how to do this with the set operators union, intersect and minus.
- Hierarchical Queries: Often a table stores rows with a parent-child relationship. For example, managers to their employees, folders on your computer, and family trees. This module shows you how to display parents and children next to each other using SQL.
- Merge: Sometimes when saving a record, you want to add it to the database if it doesn’t exist. But if it does, update the existing values instead. So you need an update-or-insert operation. Luckily there’s one statement that does it all: merge. This module shows you how.
- Read Consistency:If someone saves changes to a table you’re querying, what happens? At what point do you see their updates? How do you ensure you get a consistent view of the data? This module explains how Oracle Database‘s read consistency model works and discusses the implications for your code.
Course Details: Oracle Advanced SQL