Creating, Reading, Updating, and Deleting (CRUD)
Names such as SQLite and MySQL emphasize that all access to a database is via the Structured Query Language (SQL). In most cases, Rails will take care of this for you, but that is completely up to you. As you will see, you can provide clauses or even entire SQL statements for the database to execute.
If you are familiar with SQL already, as you read this section take note of how Rails provides places for familiar clauses such as select, from, where, group by, and so on. If you are not already familiar with SQL, one of the strengths of Rails is that you can defer knowing more about such things until you actually need to access the database at this level.
In this section, we’ll continue to work ...