This chapter covers one of the most important aspects of any application, that is, the interaction with database systems. This will take us through how Flask can connect to database systems, define models, and query the databases for the retrieval and feeding of data. Flask has been designed to be flexible enough to support any database. The simplest way would be to use the direct SQLite3 package, which is a DB-API 2.0 interface and does not give an actual object-relational mapper (ORM). Here, we need to use SQL queries to talk with the database. This approach is not recommended for large projects as it can eventually become a nightmare to maintain the application. Also, with this approach, the models are virtually non-existent and everything happens in the view functions, where we write queries to interact with the database.
In this chapter, we will talk...
