Database Views in Your ERD: Read-Only Entities, Not Fake Tables

Disclosure: I build Schemity , a desktop ERD tool - this post is from our blog and uses it for the examples. TL;DR: Database views carry real responsibilities - reporting layers, security boundaries, API surfaces - but ERD tools either leave them out entirely (DBML has no view support despite requests since 2022) or draw them as if they were ordinary tables. Schemity displays views and materialized views as read-only entities with italic names and a bold view or mview token in the entity footer, so derived relations are distinguishable from base tables at a glance, and they can be imported into context views like any other entity. A database view belongs in your ERD, but not disguised as a table: it is a derived, read-only relation, and the diagram should say so at a glance. Schemity draws views and materialized views as read-only entities with italic names - present on the canvas, visually distinct from the base tables they are built on. That sentence would be unremarkable if the rest of the tooling world agreed with it. Mostly, it does not. In most ERD tools your views are simply absent, and in the rest they are dressed up as something they are not. The reporting layer your diagram pretends does not exist Views are not decoration. They are where schemas put their public face: the reporting layer that joins five tables into one readable relation, the security boundary that exposes a subset of columns to an application role, the compatibility shim that survives a refactor. On Supabase , views are how you shape what PostgREST exposes as an API. A materialized view may be the single most performance-critical object in an analytics schema. Whoever reads your diagram to understand the system needs to see them. Yet the diagram usually cannot show them. DBML - the schema language behind dbdiagram.io - has no syntax for views at all: a user proposed designing views with join definitions in December 2022, others were still upvoting the request in July 2024, and there has be