We are now firmly involved in the world of databases and have spent some time thinking about how we would go about organizing our data and learning about the process by which data is laid out into tables (normalization). We have also begun to learn about SQL, including the data types it offers us and how it is used to create and destroy databases and tables.
Now that we have databases and tables with defined structures and implied relationships, we will spend the next chapter talking about how to start working with data in them. We will first learn how to add data to our tables, and then look at the various ways in which we can retrieve it (including sorting). We will also look at how to remove data from tables, and look at how to modify the set of columns available in a table. Finally, we will look at some more advanced SQL features, such as calling functions and grouping data values in the results.