[Bug]: Database selector shows system/maintenance databases (e.g. postgres) alongside user databases

[marwan562]

Before Submitting

• I searched existing issues and discussions to avoid creating a duplicate.
• I can reproduce this on the latest version of db-studio.

db-studio Version

1.13.0

Product Surface

Web App

Database Type

PostgreSQL

Other Database Type

No response

What happened?

With a single-database connection string in .env:

DATABASE_URL=postgresql://marwanhassan@localhost:5432/db_studio_test

the database selector in the bottom-left sidebar lists 2 databases: db_studio_test and postgres — even though only db_studio_test was ever created/connected. The footer also reports Databases: 2.

postgres is PostgreSQL's auto-created maintenance database (initdb creates it on every cluster). It is real, but showing it next to the application database is confusing — it looks like a second running database the user does not recognize.

Root cause: GET /databases → PgAdapter.getDatabasesList() (packages/server/src/adapters/pg/pg.adapter.ts) enumerates the whole server:

SELECT d.datname AS name, ...
FROM pg_catalog.pg_database d
WHERE d.datistemplate = false
ORDER BY d.datname;

postgres has datistemplate = false just like any user DB, so it is always returned. Same class of issue in the other adapters (only MSSQL filtered system DBs): MySQL leaks information_schema/mysql/performance_schema/sys, MongoDB leaks admin/config/local, SQLite lists internal temp.

Steps to Reproduce

1. Set DATABASE_URL=postgresql://<user>@localhost:5432/db_studio_test in .env
2. Run bun run dev and open the web app
3. Look at the bottom-left Database selector → shows db_studio_test and postgres; footer shows Databases: 2
4. Confirm server-side: SELECT datname FROM pg_database WHERE datistemplate = false; returns both rows

Expected Behavior

The selector lists only user-created databases (db_studio_test, count 1). System/maintenance databases stay hidden unless the connection string points at one of them (e.g. DATABASE_URL=.../postgres should still list postgres).

I have this fix implemented and verified locally across all five adapters (filter system DBs, always keep the currently-connected DB visible) and can open a PR if the maintainers agree with the approach.

Screenshots

Screenshot 1 — web app showing two databases (the bug)

The bottom-left Database selector lists two databases even though only one is configured:

• db_studio_test (selected)
• postgres ← unexpected maintenance database

The footer also reports Databases: 2.

Screenshot 2 — .env with a single database (expected setup)

Only one database is connected to db-studio:

DATABASE_URL=postgresql://marwanhassan@localhost:5432/db_studio_test

Logs / Error Output

No errors — the endpoint behaves as coded; this is a UX/correctness issue, not a crash.


     datname
------------------
 db_studio_test
 postgres

Environment

OS: macOS
Browser: Chrome
Bun version: 1.4.0