Support other SQL dialects (MySQL, PostgreSQL)

.changes/unreleased/added-20251012-201335.yaml

@@ -0,0 +1,5 @@
+kind: added
+body: Support PostgreSQL as library or CLI
+time: 2025-10-12T20:13:35.619382+02:00
+custom:
+    Issue: ""

.changes/unreleased/added-20251013-003617.yaml

@@ -0,0 +1,5 @@
+kind: added
+body: Support MySQL databases as library or via CLI
+time: 2025-10-13T00:36:17.19928+02:00
+custom:
+    Issue: ""

.changes/unreleased/deprecated-20251011-193908.yaml

@@ -0,0 +1,5 @@
+kind: deprecated
+body: Limit Drift::Migrator to DB::Database types
+time: 2025-10-11T19:39:08.945847+02:00
+custom:
+    Issue: ""

.changes/unreleased/improved-20251011-195702.yaml

@@ -0,0 +1,5 @@
+kind: improved
+body: Abstract Migrator SQL operations as Dialect implementation
+time: 2025-10-11T19:57:02.013986+02:00
+custom:
+    Issue: ""

.changes/unreleased/improved-20251012-125124.yaml

@@ -0,0 +1,5 @@
+kind: improved
+body: Optimize rollback plan calculations and memory usage
+time: 2025-10-12T12:51:24.699334+02:00
+custom:
+    Issue: ""

.changes/unreleased/internal-20251012-133617.yaml

@@ -0,0 +1,5 @@
+kind: internal
+body: Adds PostgreSQL container for development/testing
+time: 2025-10-12T13:36:17.161299+02:00
+custom:
+    Issue: ""

.changes/unreleased/internal-20251012-151331.yaml

@@ -0,0 +1,5 @@
+kind: internal
+body: Move SQLite3 dependency to only development mode
+time: 2025-10-12T15:13:31.081418+02:00
+custom:
+    Issue: ""

.changes/unreleased/internal-20251013-003809.yaml

@@ -0,0 +1,5 @@
+kind: internal
+body: Add MySQL container for local and CI testing
+time: 2025-10-13T00:38:09.800223+02:00
+custom:
+    Issue: ""

.github/workflows/test.yml

@@ -29,8 +29,39 @@ jobs:
 
   test:
     runs-on: ubuntu-latest
+    services:
+      mysql:
+        image: mysql:5.7
+        env:
+          MYSQL_DATABASE: drift_test
+          MYSQL_USER: drift
+          MYSQL_PASSWORD: drift
+          MYSQL_ROOT_PASSWORD: drift_root
+        options: >-
+          --health-cmd="mysqladmin ping -h localhost"
+          --health-interval=10s
+          --health-timeout=5s
+          --health-retries=5
+        ports:
+          - 3306:3306
+      postgres:
+        image: postgres:18-alpine
+        env:
+          POSTGRES_DB: drift_test
+          POSTGRES_USER: drift
+          POSTGRES_PASSWORD: drift
+        options: >-
+          --health-cmd pg_isready
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
+        ports:
+          - 5432:5432
     steps:
       - uses: actions/checkout@v4
       - uses: crystal-lang/install-crystal@v1
       - run: shards install
       - run: crystal spec
+        env:
+          MYSQL_DB_URL: mysql://drift:drift@localhost:3306/drift_test
+          POSTGRES_DB_URL: postgres://drift:drift@localhost:5432/drift_test

Makefile

@@ -27,7 +27,7 @@ export FIXGID
 # Make `help` the default task
 .DEFAULT_GOAL := help
 
-.PHONY: build console logs restart setup start stop help
+.PHONY: console dev help restart setup stop
 
 console: ## start a console session
 	@docker compose exec app sh -i 2>/dev/null || docker compose run --rm app -- sh -i

README.md

@@ -96,11 +96,15 @@ in reverse order using the information on the previously mentioned table.
 ## Requirements
 
 Drift CLI is a standalone, self-contained executable capable of connecting to
-SQLite databases.
+the following databases (dialects):
+
+* MySQL
+* PostgreSQL
+* SQLite3
 
 Drift (as library) only depends on Crystal's
 [`db`](https://github.com/crystal-lang/crystal-db) common API. To use it with
-to specific adapters, you need to add the respective dependencies and require
+specific adapters, you need to add the respective dependencies and require
 them part of your application. See more about in the
 [library usage](#as-library-crystal-shard) section.
 
@@ -189,7 +193,35 @@ application:
 require "sqlite3"
 require "drift"
 
-db = DB.connect "sqlite3:app.db"
+db = DB.open "sqlite3:app.db"
+
+migrator = Drift::Migrator.from_path(db, "database/migrations")
+migrator.apply!
+
+db.close
+```
+
+For a MySQL database:
+
+```crystal
+require "mysql"
+require "drift"
+
+db = DB.open "mysql://user:password@localhost/dbname"
+
+migrator = Drift::Migrator.from_path(db, "database/migrations")
+migrator.apply!
+
+db.close
+```
+
+Or for a PostgreSQL database:
+
+```crystal
+require "pg"
+require "drift"
+
+db = DB.open "postgres://user:password@localhost/dbname"
 
 migrator = Drift::Migrator.from_path(db, "database/migrations")
 migrator.apply!
@@ -237,7 +269,7 @@ require "drift"
 
 Drift.embed_as("my_migrations", "database/migrations")
 
-db = DB.connect "sqlite3:app.db"
+db = DB.open "sqlite3:app.db"
 
 migrator = Drift::Migrator.new(db, my_migrations)
 migrator.apply!
@@ -251,6 +283,32 @@ bundling all the migrations found in `database/migrations` directory.
 When using classes or modules, you can also define instance or class methods
 by prepending `self.` to the method name to use by Drift.
 
+## Development
+
+### Running tests
+
+By default, tests run against all supported databases (MySQL, PostgreSQL,
+SQLite3).
+
+To skip specific databases:
+
+```console
+$ SKIP_MYSQL=true crystal spec        # Skip MySQL tests
+$ SKIP_POSTGRESQL=true crystal spec   # Skip PostgreSQL tests
+```
+
+Start database services with Docker Compose:
+
+```console
+$ docker compose up -d mysql postgres
+```
+
+Stop database services:
+
+```console
+$ docker compose down
+```
+
 ## Contribution policy
 
 Inspired by [Litestream](https://github.com/benbjohnson/litestream) and

compose.yaml

@@ -3,15 +3,57 @@ services:
     image: ghcr.io/luislavena/hydrofoil-crystal:${CRYSTAL_VERSION:-1.16}
     command: overmind start -f Procfile.dev
     working_dir: /workspace/${COMPOSE_PROJECT_NAME}
+    depends_on:
+      - mysql
+      - postgres
     environment:
       # Workaround Overmind socket issues with Vite
       # Ref: https://github.com/luislavena/hydrofoil-crystal/issues/66
       - OVERMIND_SOCKET=/tmp/overmind.sock
       # Disable Shards' postinstall
       - SHARDS_OPTS=--skip-postinstall
+      # Test DBs
+      - MYSQL_DB_URL=mysql://drift:drift@mysql:3306/drift_test
+      - POSTGRES_DB_URL=postgres://drift:drift@postgres:5432/drift_test
 
     # Set these env variables using `export FIXUID=$(id -u) FIXGID=$(id -g)`
     user: ${FIXUID:-1000}:${FIXGID:-1000}
 
     volumes:
       - .:/workspace/${COMPOSE_PROJECT_NAME}:cached
+
+  mysql:
+    image: mysql:8.0-oracle
+    command: --default-authentication-plugin=mysql_native_password
+    environment:
+      MYSQL_DATABASE: drift_test
+      MYSQL_USER: drift
+      MYSQL_PASSWORD: drift
+      MYSQL_ROOT_PASSWORD: drift_root
+    healthcheck:
+      test: ["CMD", "mysqladmin", "ping", "-h", "localhost"]
+      interval: 5s
+      timeout: 5s
+      retries: 3
+    volumes:
+      - mysql:/var/lib/mysql
+
+  postgres:
+    image: postgres:18-alpine
+    environment:
+      POSTGRES_DB: drift_test
+      POSTGRES_USER: drift
+      POSTGRES_PASSWORD: drift
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U $$POSTGRES_USER -d $$POSTGRES_DB"]
+      interval: 5s
+      timeout: 5s
+      retries: 3
+    volumes:
+      - postgres:/var/lib/postgresql
+
+volumes:
+  mysql:
+    driver: local
+  postgres:
+    driver: local

shard.yml

@@ -11,6 +11,14 @@ dependencies:
   db:
     github: crystal-lang/crystal-db
     version: ~> 0.14.0
+development_dependencies:
+  mysql:
+    github: crystal-lang/crystal-mysql
+    version: ~> 0.17.0
+  pg:
+    github: will/crystal-pg
+    # FIXME: lock until new crystal-pg release
+    commit: c5b8ac1ac5713fc58f974d8a4327887a0b297594
   sqlite3:
     github: crystal-lang/crystal-sqlite3
     version: ~> 0.22.0

spec/drift/dialect_spec.cr

@@ -0,0 +1,50 @@
+# Copyright 2022 Luis Lavena
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+require "../spec_helper"
+
+require "mysql"
+require "pg"
+require "sqlite3"
+
+describe Drift::Dialect do
+  describe ".from_db" do
+    it "detects SQLite3 dialect" do
+      db = DB.open("sqlite3:%3Amemory%3A")
+      dialect = Drift::Dialect.from_db(db)
+
+      dialect.should be_a(Drift::Dialect::SQLite3)
+
+      db.close
+    end
+
+    it "detects PostgreSQL dialect" do
+      db = DB.open(ENV["POSTGRES_DB_URL"]? || "postgres://drift:drift@localhost:5432/drift")
+      dialect = Drift::Dialect.from_db(db)
+
+      dialect.should be_a(Drift::Dialect::PostgreSQL)
+
+      db.close
+    end
+
+    it "detects MySQL dialect" do
+      db = DB.open(ENV["MYSQL_DB_URL"]? || "mysql://drift:drift@localhost:3306/drift_test")
+      dialect = Drift::Dialect.from_db(db)
+
+      dialect.should be_a(Drift::Dialect::MySQL)
+
+      db.close
+    end
+  end
+end