Drupal, unlike plain old blog software, gives you the ability to create custom content object types with backing storage in the database as custom tables, doing all this without requiring any programming knowledge. When you create a new custom Content Type and add fields to it, in effect, you are creating a new database table for those fields.
Drupal also gives you ways to access and query the data without writing code. The most powerful form of this is Views, which every Drupal site should install as soon as starting. In the Views UI, you can select which fields (database columns...