In this chapter, you mastered how to configure a database connection and execute SQL queries from scratch with DAO support of the framework. Next, you found out how to use Gii and got to know about the advantages it has in creating models from the database table structure. Gii creates models that extend the ActiveRecord class and through its use, you finally learned to manipulate data. All the examples are accompanied with a visualization grid that shows data, which is graphically enhanced by Bootstrap's presence in Yii2.

We carefully analyzed the common topic of tables' relationships, which must be managed in models and then displayed in views.

At the end of the chapter, after you learned to manipulate data with ActiveRecord, you wrote a complete flow to save data from a HTML form to a database. Finally, you learned the importance of setting the GMT time zone in date/time fields and using other database sources in the same application in order to make a backup of the primary database.

In the next chapter, you will learn to use and customize the grid widget to improve data visualization.