Oracle SQL 入門

Sometimes, you need to perform operations on a group of data, and get aggregated results. This second chapter will show you how. You will also learn about data types.

What if your data is spread across multiple tables? This third chapter will show you how to join several tables, and how to perform queries and operations on them.

By now, you already have some solid basics. Let's take it a step further and understand how Oracle SQL interprets your queries. You will then learn how to customize your outputs, handle missing values, and how to convert data from one type to another.