How do I create a relational database in Tana like in Notion or Airtable?

Because Tana is a graph, building relational databases is easy.

Think of supertags as databases, and fields as columns in a database

Let's use an example:

• You have two supertags: #person and #project. You want to relate the two by assigning a team lead to each project that draws from person.
• To relate each project to one team lead, we can make an Instance field called Team lead in the project. This allows us to select the #person supertag so this field will now create a dropdown of options from every instance of the person supertag.
• Now, every time you assign a team lead to every project, on the other side you can look at a person and see what projects they are noted as Team lead for in the Reference section.

There are many other ways to relate one database to another in Tana that go beyond what relational databases can do. That's because all information in Tana is stored as a graph, and on top of this we have flexible ways to build schemas with supertags and fields. It's everything a relational database has, with much more freedom and flexibility in the long run.