Drupal database schema and Node

Posted under » Drupal updated on 24 Mar 2025

Drupal's database schema is more complicated because it has revisions. Drupal is a CMS that was designed as a news or publishing platform. So the editor can keep track of the changes to the article and have several layers of approval process before the content is published.

I will not cover all the tables but only regarding content.

Node

Node table is the heart of it all. A node has nid, vid, type, uuid, langcode where v stands for version.

• nid is the one you see in the url eg. /node/2. Otherwise known as entity_id
• vid is version id. Otherwise known as revision_id
• Type is content type. Eg. Question or Notes
• UUID or Universally Unique IDentifier, makes it possible to maintain connections between different entities. It is like node id. You can have nid 1 but there could be vid 1. So 1 is not unique but UUID is. UUID looked like f9277e7d-f45d-4736i. The purpose of node table is to hold the UUID.

node_field_data

This is an extension of the node table. Thus you will get the same nid, vid and type in node and node_field_data.

• title. The purpose of node table is to hold the title
• created
• changed
• promote and sticky

node__body

Notice the double __ underscore. It means it is a field in a content type.

This is an extension of the node_field_data table. However, the field names are changed. You will get the nid (entity_id), vid (revision_id) and type (bundle) in node_field_data and node__body.

• body_value
• body_summary - Not used in some templates
• body_format - HTML?
• deleted
• delta - The sequence number for this data item, used for multi-value fields

Note that there are many node__tablename. These are the fields similar to node__body. For example. node__field_image

node__comment

This is something like node__body. However, comments are like sub node or another module. The contents are inside the comment table.

Drupal revision tables »