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PostgreSQL to ER Diagram

Paste your DDL or a raw pg_dump --schema-only dump — schemas, identity columns, and ALTER TABLE foreign keys all land where they belong.

SQL input — CREATE TABLE · DDL · dumppostgres

CREATE TABLE public.users (
  id bigint GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
  email text NOT NULL UNIQUE,
  display_name text,
  created_at timestamptz NOT NULL DEFAULT now()
);

CREATE TABLE public.profiles (
  user_id bigint PRIMARY KEY,
  bio text,
  website text
);

CREATE TABLE public.posts (
  id bigint GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
  author_id bigint NOT NULL,
  title text NOT NULL,
  body text,
  status text NOT NULL DEFAULT 'draft',
  published_at timestamptz,
  metadata jsonb
);

CREATE TABLE public.comments (
  id bigint GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
  post_id bigint NOT NULL,
  commenter_id bigint NOT NULL,
  body text NOT NULL,
  created_at timestamptz NOT NULL DEFAULT now()
);

CREATE TABLE public.tags (
  id serial PRIMARY KEY,
  slug text NOT NULL UNIQUE
);

CREATE TABLE public.post_tags (
  post_id bigint NOT NULL,
  tag_id bigint NOT NULL,
  PRIMARY KEY (post_id, tag_id)
);

-- the way pg_dump actually writes foreign keys:
ALTER TABLE ONLY public.profiles
  ADD CONSTRAINT profiles_user_id_fkey FOREIGN KEY (user_id) REFERENCES public.users(id) ON DELETE CASCADE;
ALTER TABLE ONLY public.posts
  ADD CONSTRAINT posts_author_id_fkey FOREIGN KEY (author_id) REFERENCES public.users(id) ON DELETE RESTRICT;
ALTER TABLE ONLY public.comments
  ADD CONSTRAINT comments_post_id_fkey FOREIGN KEY (post_id) REFERENCES public.posts(id) ON DELETE CASCADE;
ALTER TABLE ONLY public.comments
  ADD CONSTRAINT comments_commenter_id_fkey FOREIGN KEY (commenter_id) REFERENCES public.users(id);
ALTER TABLE ONLY public.post_tags
  ADD CONSTRAINT post_tags_post_id_fkey FOREIGN KEY (post_id) REFERENCES public.posts(id) ON DELETE CASCADE;
ALTER TABLE ONLY public.post_tags
  ADD CONSTRAINT post_tags_tag_id_fkey FOREIGN KEY (tag_id) REFERENCES public.tags(id) ON DELETE CASCADE;

postgresSample: · ·

Diagram—

Your diagram renders here.

Parser coverage

What we parse in postgres

Schemas — public, auth, storage… grouped in labeled containers
Identity columns — SERIAL and GENERATED … AS IDENTITY render as PK-safe
Postgres types — jsonb, text[], timestamptz, numeric(12,2) shown verbatim
Separated FKs — ALTER TABLE … ADD FOREIGN KEY, the pg_dump way, reattached automatically

From your database

Get just the schema

pg_dump --schema-only dbname > schema.sql

Structure only, no data. Paste schema.sql above — no connection strings, no credentials.

FAQ

Questions, answered

How do I generate an ER diagram from a PostgreSQL schema?

Run pg_dump --schema-only, paste the output above — or paste CREATE TABLE statements directly.

Does it work with pg_dump output?

Yes, including dumps where foreign keys are added by separate ALTER TABLE statements.

Does it connect to my Postgres database?

No — and that's the point. No credentials, no network access to your DB; just paste the DDL.

Are Postgres schemas (namespaces) shown?

Yes — non-default schemas get their own labeled group in the diagram.

More converters

PostgreSQL to ER Diagram

What we parse in postgres

Get just the schema

Questions, answered

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