Relationship Between Post, Taxonomy, & Terms

Let’s talk about the relationship between the post, taxonomy, and terms. To an author, the relationship looks like it’s the interface where s/he writes and configures the content. But this interface is just a graphic representation of the content in the database. Therefore, this episode is a technical relationship discussion.

WordPress gives us a graphic that shows the relationship of taxonomies to their terms. This table shows you that categories are hierarchical, meaning each term can have a child, grandchildren, and so on. Think of it like a tree, where there are levels. Tags and post formats can have just one level.

On a technical basis, the relationship between post, taxonomy, and terms is defined within the database. It is defined in the following database tables:

• wp_posts
• wp_term_relationships
• wp_term_taxonomy
• wp_termmeta
• wp_terms

Posts can have many taxonomies and many terms. A taxonomy can have many terms. Terms have one taxonomy and many posts. Notice the words that I’m using: one-to-many and many-to-many. These terms define our database relationships and then how you architect the tables. This is why we have so many database tables. Let’s talk about that.

Key Take-aways

The key points and take-aways from this episode are:

• The editor in the back-end is an interface. It’s being populated by code. The code pulls and saves the content and configuration data to/from the database.
• Therefore, technically the data is in the database. The interface represents the data in the database.
• The relationship is a many-to-many.

Want to know more about the database?

If you want to know more about the database, then go do these labs:

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