Good practices working with databases I'm learning Drupal, and I want to develop a website where the main thing is its database.

I already have the Extended Entity-Relationship Model of the database (kind of complex).

What's the right direction to take when creating a database to be used by Drupal, create it manually and do the queries in Drupal using PHP, as it were a PHP+MySQL site from scratch?
Does Drupal provide an easier way to do this?

Edit:
I'm not a Drupal experienced developer. What I want to know is:  


When working with databases, is any better way of doing this that querying the database using SQL syntax, like if I were developing a PHP+MySQL single page?


I just want to know what Drupal developers usually doe when they want to create a database, insert data, modify data, or do some queries and show the data to the users.
Your entity-relationship model is likely going to map to what we call 'Content types' in Drupal.

Content types are defined using the Content Construction Kit module, commonly referred to as CCK.

With CCK, you point-and-click to define what fields you want the content type to have - text fields, numbers, links, references to other content types, references to users in your Drupal site.

With the content types defined, you can figure out what kind of lists for that content you want - tabular, blog-style, etc, and use the Views module to create that listing.  Views is a point-and-click query builder, complete with sorting, filtering, access control, dynamic URL arguments, and relationships (think joins) to other content types.

That's typically how 'databases' are done in Drupal - but you don't have to do anything with the database at all, really.

If you've got a really specific use case that can't be solved with some combination of the 7000 or so contributed Drupal modules, then it might be time to grab a copy of 'Pro Drupal Development' and learn module development to integrate your custom module into the rest of Drupal to meet your exact need.