Performing mathematical operations with a set
Sets are a fundamental concept in mathematics with far-reaching applications in computer science, particularly within the realm of databases. Databases serve as the backbone of countless applications, and sets play a crucial role in their design and operation.
When we construct a query to retrieve data from a relational database (such as Oracle, Microsoft SQL Server, MySQL, etc.), we are essentially using set notation to define the desired result. The database, in turn, returns a set of data that matches our criteria.
SQL queries allow us to specify the scope of the data we want to retrieve. We can select all records from a table, or we can narrow down the search to a specific subset based on certain conditions. Furthermore, SQL leverages set operations to perform various types of data manipulation. The concept of joins in SQL is fundamentally based on set operations. Here are some common examples:
- Union: combining data from two or more tables...
