How to connect to the database externally under discourse container deployment method, for example using DBeaver

You’d need to look at the two-container setup, or find some other way to assign a password to the Discourse user and expose the postgres port, something like

expose:
  - "80:80"   # http
  - "443:443" # https
  - "127.0.0.1:5432:5432"

But what problem are you solving? Maybe just use Discourse Data Explorer.

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