Data normalization is a process in database design that aims to reduce data redundancy and improve data integrity. In the context of relational databases, normalization involves organizing tables, columns, and relationships in a way that:
Eliminates redundant data (so that the same data is not stored in multiple places).
Ensures that each table has a primary key and that each column in the table depends only on the primary key (i.e., follows the rules of functional dependencies).
There are several normalization forms (1NF, 2NF, 3NF, BCNF, etc.), each with its own set of rules and conditions. As you progress from one normalization form to another, the database becomes more normalized.
When I mentioned that removing profile_id from the Bookmark model would make the data model more normalized, I meant that it would eliminate the direct relationship between Profile and Bookmark and reduce redundancy. Instead, the relationship would be established indirectly through the Bookmark_Folder model.
However, increased normalization is not always the best solution, as it can sometimes make queries more complex and negatively impact performance. In your case, having profile_id in both Bookmark and Bookmark_Folder models simplifies the queries and relationships, which could be beneficial for your specific requirements.
Your Bookmark and Bookmark_Folder models look good. However, you asked if it's right to have profile_id on both models. The answer depends on your specific requirements. Let me explain the current setup:
Each Bookmark is associated with a Profile through profile_id. This means that you can retrieve all bookmarks created by a specific user.
Each Bookmark_Folder is also associated with a Profile through profile_id. This means that you can retrieve all bookmark folders created by a specific user.
Bookmark is associated with Bookmark_Folder through folder_id. This allows you to retrieve all bookmarks in a specific folder.
With this setup, you can achieve all the functionalities you mentioned earlier, such as listing all bookmarked news articles for a user, retrieving all bookmark folders for a user, and showing bookmarks within a specific folder.
Having profile_id on both models helps to establish a direct relationship between bookmarks and profiles, as well as between bookmark folders and profiles. This makes querying the data more straightforward.
However, you could also choose to remove profile_id from the Bookmark model and rely on the relationship between Bookmark and Bookmark_Folder to indirectly link bookmarks to profiles. This would make the data model more normalized, but it might make some queries more complex.
In summary, your current setup with profile_id on both models should work well for your requirements.
