Define the path to the database file using getDatabasesPath() from the
  sqflite package, combined with the join function from the path package.

Open the database with the openDatabase() function from sqflite.

Note:
  In order to use the keyword await, the code must be placed
  inside an async function. You should place all the following
  table functions inside void main() async {}.

4. Create the dogs table

The id is a Dart int, and is stored as an INTEGER SQLite
Datatype. It is also good practice to use an id as the primary
key for the table to improve query and update times.

The name is a Dart String, and is stored as a TEXT SQLite
Datatype.

The age is also a Dart int, and is stored as an INTEGER
Datatype.

For more information about the available Datatypes that can be stored in a
SQLite database, see the official SQLite Datatypes documentation.