Rust · SQL

Diesel migrations, drawn as a database diagram

Rust's Diesel migrations: one directory per change with up.sql and down.sql. SchemaDrawer runs diesel_cli 2.3.13 with the postgres against a throw-away database of the engine you choose and returns an SVG of the schema it produces.

Get startedDiesel documentation

What to upload

Upload the migrations directory: one folder per migration named <version>_<title>, each holding up.sql and, optionally, down.sql.

The sample below is the PetClinic schema written for Diesel, one of the sets SchemaDrawer's own tests draw on every engine:

migrations/
├── 2026-09-21-120000_create_owners_and_pets/
│   ├── down.sql
│   └── up.sql
├── 2026-09-21-120100_create_vets/
│   ├── down.sql
│   └── up.sql
└── 2026-09-21-120200_create_visits/
    ├── down.sql
    └── up.sql

Formats

Plain SQL.

How it runs

diesel migration run. The database is a fresh PostgreSQL, MySQL, MariaDB, SQL Server, Oracle or SQLite container in the version you ask for; nothing of yours is touched.

Databases you can draw Diesel on

PostgreSQL 10, 11, 12, 13, 14, 15, 16, 17, 18 MySQL 8.0, 8.4, 9 MariaDB 10.6, 11.4, 11.8, 12 SQL Server Oracle SQLite

Not offered for Diesel: SQL Server, Oracle. The tool ships no driver for them, so nothing could run.

At a glance

Runs
diesel_cli 2.3.13 with the postgres, mysql and sqlite backends
API value
migrationType=DIESEL
Engines
4 of 6: PostgreSQL, MySQL, MariaDB, SQLite
Output
SVG diagram with tables, columns and types, primary and foreign keys
Price
Free today; enterprise plans are coming
Example

The PetClinic schema in Diesel

Owners, pets, types, vets, specialties and visits: the same seven tables every sample set on this site creates. These are the exact files the tests upload.

DROP TABLE pets;
DROP TABLE types;
DROP TABLE owners;

CREATE TABLE owners
(
    id         INT          NOT NULL,
    first_name VARCHAR(50)  NOT NULL,
    last_name  VARCHAR(50)  NOT NULL,
    address    VARCHAR(255),
    city       VARCHAR(80),
    telephone  VARCHAR(20),
    CONSTRAINT pk_owners PRIMARY KEY (id)
);

CREATE TABLE types
(
    id   INT         NOT NULL,
    name VARCHAR(80) NOT NULL,
    CONSTRAINT pk_types PRIMARY KEY (id)
);

CREATE TABLE pets
(
    id         INT         NOT NULL,
    name       VARCHAR(50) NOT NULL,
    birth_date DATE,
    type_id    INT         NOT NULL,
    owner_id   INT         NOT NULL,
    CONSTRAINT pk_pets PRIMARY KEY (id),
    CONSTRAINT fk_pets_types FOREIGN KEY (type_id) REFERENCES types (id),
    CONSTRAINT fk_pets_owners FOREIGN KEY (owner_id) REFERENCES owners (id)
);

DROP TABLE vet_specialties;
DROP TABLE specialties;
DROP TABLE vets;

CREATE TABLE vets
(
    id         INT         NOT NULL,
    first_name VARCHAR(50) NOT NULL,
    last_name  VARCHAR(50) NOT NULL,
    CONSTRAINT pk_vets PRIMARY KEY (id)
);

CREATE TABLE specialties
(
    id   INT         NOT NULL,
    name VARCHAR(80) NOT NULL,
    CONSTRAINT pk_specialties PRIMARY KEY (id)
);

CREATE TABLE vet_specialties
(
    vet_id       INT NOT NULL,
    specialty_id INT NOT NULL,
    CONSTRAINT pk_vet_specialties PRIMARY KEY (vet_id, specialty_id),
    CONSTRAINT fk_vet_specialties_vets FOREIGN KEY (vet_id) REFERENCES vets (id),
    CONSTRAINT fk_vet_specialties_specialties FOREIGN KEY (specialty_id) REFERENCES specialties (id)
);

DROP TABLE visits;

CREATE TABLE visits
(
    id          INT NOT NULL,
    pet_id      INT NOT NULL,
    visit_date  DATE,
    description VARCHAR(255),
    CONSTRAINT pk_visits PRIMARY KEY (id),
    CONSTRAINT fk_visits_pets FOREIGN KEY (pet_id) REFERENCES pets (id)
);
diagram.svg
ER diagram of the PetClinic schema drawn by SchemaDrawer: owners, pets, types, vets, specialties, vet_specialties and visits with their columns, primary keys and foreign keys

Every variant of the sample produces these seven tables. This diagram was drawn from the Flyway variant on PostgreSQL 18; on MySQL the types read INT and VARCHAR, on Oracle the names are upper case.

Run it

Draw your Diesel migrations

One multipart request queues the drawing; poll the job until it succeeds and download the SVG. Or let the GitHub Action do it and open a pull request with the diagram.

With curl

curl -X POST https://schemadrawer.com/api/v1/drawing \
  -H "Request-Id: $(uuidgen)" \
  -F "userId=5f0c1d2e-3a4b-4c5d-8e6f-7a8b9c0d1e2f" \
  -F "migrationType=DIESEL" \
  -F "databaseType=POSTGRESQL" \
  -F "version=18" \
  -F "files=@migrations/2026-09-21-120000_create_owners_and_pets/down.sql;filename=2026-09-21-120000_create_owners_and_pets/down.sql" \
  -F "files=@migrations/2026-09-21-120000_create_owners_and_pets/up.sql;filename=2026-09-21-120000_create_owners_and_pets/up.sql" \
  -F "files=@migrations/2026-09-21-120100_create_vets/down.sql;filename=2026-09-21-120100_create_vets/down.sql" \
  -F "files=@migrations/2026-09-21-120100_create_vets/up.sql;filename=2026-09-21-120100_create_vets/up.sql" \
  -F "files=@migrations/2026-09-21-120200_create_visits/down.sql;filename=2026-09-21-120200_create_visits/down.sql" \
  -F "files=@migrations/2026-09-21-120200_create_visits/up.sql;filename=2026-09-21-120200_create_visits/up.sql"
# {"jobId":"0b6e2f4c-8d1a-4c3e-9f7a-2a5b6c7d8e9f"}

Then poll GET https://schemadrawer.com/api/v1/drawing/{jobId} until status is SUCCESS and fetch diagramUrl. Details in the getting started guide and the API reference.

With the GitHub Action

- uses: schemadrawercom/action@v1
  with:
    sql-directory: migrations
    output-path: docs/schema-diagram.svg
    migration-type: DIESEL
    database-type: POSTGRESQL
    database-version: '18'
    github-token: ${{ secrets.GITHUB_TOKEN }}

The action uploads the directory, waits for the diagram and opens a pull request with the SVG. See the action reference.

Good to know

  • down.sql is never executed, a diesel.toml in the upload is not read and no schema.rs is generated.
  • The __diesel_schema_migrations table is left out of the diagram.
  • Diesel supports PostgreSQL, MySQL, MariaDB and SQLite, so SQL Server and Oracle are not offered for it.
  • A drawing may take up to 120 seconds; a job that waits in the queue longer than 10 minutes fails rather than draws. Uploads of up to 100 MB and 2000 files are accepted.
From the blog

Reading about Diesel and migrations

Draw your Diesel schema now

Upload the migration directory, get an SVG back. Free while we build it.

Get started See examples