diff --git a/.travis.yml b/.travis.yml
index f559271..f14c848 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,6 +4,21 @@ node_js:
   - "7"
   - "8"
 sudo: false
+
+before_script:
+  - mysql -e "CREATE USER grind_test;" -u root
+  - mysql -e "GRANT ALL PRIVILEGES ON *.* TO grind_test;" -u root
+  - mysql -e "CREATE DATABASE grind_orm_test;" -u root
+  - psql -c "CREATE USER grind_test SUPERUSER;" -U postgres
+  - psql -c "CREATE DATABASE grind_orm_test;" -U postgres
+
 script:
   - "npm run lint"
   - "npm test"
+
+services:
+  - mysql
+  - postgresql
+
+addons:
+  postgresql: '9.5'
diff --git a/README.markdown b/README.markdown
index 5a9640a..b099a9d 100644
--- a/README.markdown
+++ b/README.markdown
@@ -16,6 +16,22 @@ Grind ORM provides an integrated ORM for [Grind](https://github.com/grindjs/fram
 
 Full documentation for Grind ORM is available on the [Grind website](https://grind.rocks/docs/guides/orm).
 
+## Testing MySQL and PostgreSQL
+Install [MySQL](https://dev.mysql.com/downloads/mysql/) and [PostgreSQL](https://www.postgresql.org/download/). Then, create users and databases:
+
+MySQL:
+```bash
+> "CREATE USER grind_test;"
+> "GRANT ALL PRIVILEGES ON `grind_orm_test`.* TO 'grind_test'@'%';"
+> "CREATE DATABASE grind_orm_test;"
+```
+
+PostgreSQL:
+```bash
+> "CREATE USER grind_test SUPERUSER;"
+> "CREATE DATABASE grind_orm_test;"
+```
+
 ## License
 
 Grind was created by [Shaun Harrison](https://github.com/shnhrrsn) and is made available under the [MIT license](LICENSE).
diff --git a/bin/ava b/bin/ava
index 36e264f..006a5c3 100755
--- a/bin/ava
+++ b/bin/ava
@@ -6,4 +6,4 @@ if [ "$NODE_VERSION" == "7" ]; then
 	FLAGS="--harmony-async-await"
 fi
 
-NODE_ENV=test node $FLAGS node_modules/.bin/ava "$@"
+NODE_ENV=test node $FLAGS node_modules/.bin/ava "$@" --serial
diff --git a/package.json b/package.json
index b541af4..7b61755 100644
--- a/package.json
+++ b/package.json
@@ -34,6 +34,8 @@
     "grind-cli": "^0.7.0",
     "grind-db": "^0.7.0",
     "grind-framework": "^0.7.1",
+    "mysql": "^2.15.0",
+    "pg": "^7.3.0",
     "sqlite": "^2.8.0"
   },
   "engines": {
diff --git a/src/MakeModelCommand.js b/src/MakeModelCommand.js
index a2e8e11..b58d944 100644
--- a/src/MakeModelCommand.js
+++ b/src/MakeModelCommand.js
@@ -3,6 +3,7 @@ import './Inflect'
 import path from 'path'
 
 export class MakeModelCommand extends Command {
+
 	name = 'make:model'
 	description = 'Create a model class'
 
diff --git a/src/Model.js b/src/Model.js
index ffdb6a3..7288f7e 100644
--- a/src/Model.js
+++ b/src/Model.js
@@ -1,3 +1,4 @@
+/* eslint-disable max-lines */
 import { Model as ObjectionModel } from 'objection'
 
 import './Inflect'
@@ -8,6 +9,7 @@ import './RelationValidator'
 const as = require('as-type')
 
 export class Model extends ObjectionModel {
+
 	static descriptiveName = null
 	static eager = null
 	static eagerFilters = null
diff --git a/src/QueryBuilder.js b/src/QueryBuilder.js
index b749b9b..3cc499f 100644
--- a/src/QueryBuilder.js
+++ b/src/QueryBuilder.js
@@ -3,6 +3,7 @@ import { QueryBuilder as ObjectionQueryBuilder } from 'objection'
 import './ModelNotFoundError'
 
 export class QueryBuilder extends ObjectionQueryBuilder {
+
 	static registeredFilters = { }
 
 	_cyclicalEagerProtection = [ ]
diff --git a/src/RelationSynchronizer.js b/src/RelationSynchronizer.js
index f87db5a..342d0b3 100644
--- a/src/RelationSynchronizer.js
+++ b/src/RelationSynchronizer.js
@@ -1,4 +1,5 @@
 export class RelationSynchronizer {
+
 	model = null
 	modelClass = null
 	relation = null
diff --git a/test/QueryBuilder.js b/test/QueryBuilder.js
index 5512ba8..5d80079 100644
--- a/test/QueryBuilder.js
+++ b/test/QueryBuilder.js
@@ -19,7 +19,7 @@ test('orFail', async t => {
 	}
 
 	try {
-		await t.context.UserModel.query().where('id', Date.now()).orFail()
+		await t.context.UserModel.query().where('id', Math.round(Date.now() / 10000)).orFail()
 		t.fail('Should have thrown an error')
 	} catch(err) {
 		if(err instanceof ModelNotFoundError) {
diff --git a/test/RelationValidator.js b/test/RelationValidator.js
index b4a0999..34d7f8b 100644
--- a/test/RelationValidator.js
+++ b/test/RelationValidator.js
@@ -4,7 +4,7 @@ import { transaction } from 'objection'
 test('validate missing', async t => {
 	try {
 		await t.context.UserAvatarModel.query().insert({
-			user_id: Date.now(),
+			user_id: Math.round(Date.now() / 10000),
 			url: 'test'
 		})
 
diff --git a/test/fixtures/config/database.json b/test/fixtures/config/database.json
index 0a7a7f2..0dadeef 100644
--- a/test/fixtures/config/database.json
+++ b/test/fixtures/config/database.json
@@ -8,6 +8,24 @@
 			"driver": "sqlite3",
 			"filename": "./database.sqlite",
 			"useNullAsDefault": true
+		},
+
+		"mysql": {
+			"driver": "mysql",
+			"host": "127.0.0.1",
+			"user": "grind_test",
+			"database": "grind_orm_test",
+			"charset": "utf8",
+			"pool": {
+				"min": 1,
+				"max": 1
+			}
+		},
+
+		"pg": {
+			"driver": "pg",
+			"host": "127.0.0.1",
+			"database": "grind_orm_test"
 		}
 
 	}
diff --git a/test/fixtures/database/migrations/01-create_users_table.js b/test/fixtures/database/migrations/01-create_users_table.js
index 1b5fcfc..6250c63 100644
--- a/test/fixtures/database/migrations/01-create_users_table.js
+++ b/test/fixtures/database/migrations/01-create_users_table.js
@@ -1,6 +1,6 @@
 export function up(db) {
 	return db.schema.createTable('users', table => {
-		table.integer('id').unsigned().primary()
+		table.increments('id').unsigned().primary()
 		table.string('name', 128).notNullable().index()
 		table.timestamps()
 	})
diff --git a/test/fixtures/database/migrations/02-create_user_avatars_table.js b/test/fixtures/database/migrations/02-create_user_avatars_table.js
index c7e6aad..aada610 100644
--- a/test/fixtures/database/migrations/02-create_user_avatars_table.js
+++ b/test/fixtures/database/migrations/02-create_user_avatars_table.js
@@ -1,6 +1,6 @@
 export function up(db) {
 	return db.schema.createTable('user_avatars', table => {
-		table.integer('id').unsigned().primary()
+		table.increments('id').unsigned().primary()
 		table.integer('user_id').unsigned().nullable().index().references('id').inTable('users').onDelete('CASCADE')
 		table.string('url', 128).notNullable().index()
 		table.timestamps()
diff --git a/test/helpers/Databases/BaseDatabase.js b/test/helpers/Databases/BaseDatabase.js
new file mode 100644
index 0000000..4910a87
--- /dev/null
+++ b/test/helpers/Databases/BaseDatabase.js
@@ -0,0 +1,37 @@
+export class BaseDatabase {
+
+	static seedTables = [ 'users', 'user_avatars' ]
+
+	static ready(app) {
+		app.config.set('database.default', this.dbName)
+	}
+
+	static async runMigration(app) {
+		await app.db.migrate.latest()
+		await app.db.seed.run()
+
+		// Reset autoincrementing, which can break when primary keys are set explicitly in seed files
+		return app.db.transaction(trx => {
+			return Promise.all(this.seedTables.map(async table => {
+				try {
+					let maxId = await trx.max('id as max').from(table)
+					maxId = maxId[0].max || 10
+
+					return this.resequence(trx, table, maxId)
+				} catch(err) {
+					throw new Error(err)
+				}
+			}))
+		})
+	}
+
+	static async resequence(/* db */) {
+		throw new Error('Subclass must implement')
+	}
+
+	static shutdown(/* app */) {
+		throw new Error('Subclass must implement')
+	}
+
+
+}
diff --git a/test/helpers/Databases/Mysql.js b/test/helpers/Databases/Mysql.js
new file mode 100644
index 0000000..6266ef4
--- /dev/null
+++ b/test/helpers/Databases/Mysql.js
@@ -0,0 +1,29 @@
+import './BaseDatabase'
+
+export class Mysql extends BaseDatabase {
+
+	static dbName = 'mysql'
+
+	static runMigration(app) {
+		return app.db.migrate.currentVersion().then(version => {
+			if(version === 'none') {
+				return super.runMigration(app)
+			}
+
+			return app.db.migrate.rollback().then(() => super.runMigration(app))
+		})
+	}
+
+	static resequence(trx, table, maxId) {
+		return trx.raw(`ALTER TABLE ${table} AUTO_INCREMENT = ${maxId + 1}`)
+	}
+
+	static async shutdown(app) {
+		try {
+			await app.db.destroy()
+		} catch(err) {
+			Log.error('Unable to destroy test db', err)
+		}
+	}
+
+}
diff --git a/test/helpers/Databases/Postgres.js b/test/helpers/Databases/Postgres.js
new file mode 100644
index 0000000..65b1c03
--- /dev/null
+++ b/test/helpers/Databases/Postgres.js
@@ -0,0 +1,29 @@
+import './BaseDatabase'
+
+export class Postgres extends BaseDatabase {
+
+	static dbName = 'pg'
+
+	static runMigration(app) {
+		return app.db.migrate.currentVersion().then(version => {
+			if(version === 'none') {
+				return super.runMigration(app)
+			}
+
+			return app.db.migrate.rollback().then(() => super.runMigration(app))
+		})
+	}
+
+	static resequence(trx, table, maxId) {
+		return trx.raw(`ALTER SEQUENCE "${table}_id_seq" RESTART WITH ${maxId + 1}`)
+	}
+
+	static async shutdown(app) {
+		try {
+			await app.db.destroy()
+		} catch(err) {
+			Log.error('Unable to destroy test db', err)
+		}
+	}
+
+}
diff --git a/test/helpers/Databases/Sqlite3.js b/test/helpers/Databases/Sqlite3.js
new file mode 100644
index 0000000..809a974
--- /dev/null
+++ b/test/helpers/Databases/Sqlite3.js
@@ -0,0 +1,30 @@
+import './BaseDatabase'
+
+const path = require('path')
+const crypto = require('crypto')
+const fs = require('fs')
+
+export class Sqlite3 extends BaseDatabase {
+
+	static dbName = 'sqlite'
+	static dbPath = path.join(__dirname, `../../fixtures/database/database-${crypto.randomBytes(4).toString('hex')}.sqlite`)
+
+	static ready(app) {
+		super.ready(app)
+		app.config.set('database.connections.sqlite.filename', this.dbPath)
+	}
+
+	static resequence(trx, table, maxId) {
+		return trx.raw(`UPDATE sqlite_sequence SET seq = ${maxId} WHERE name = '${table}'`)
+	}
+
+	static shutdown(/* app */) {
+		try {
+			// eslint-disable-next-line no-sync
+			fs.unlinkSync(this.dbPath)
+		} catch(err) {
+			Log.error('Unable to remove test db', err)
+		}
+	}
+
+}
diff --git a/test/helpers/Databases/index.js b/test/helpers/Databases/index.js
new file mode 100644
index 0000000..90e365c
--- /dev/null
+++ b/test/helpers/Databases/index.js
@@ -0,0 +1,9 @@
+import './Postgres'
+import './Sqlite3'
+import './Mysql'
+
+export const Databases = {
+	[Postgres.dbName]: Postgres,
+	[Sqlite3.dbName]: Sqlite3,
+	[Mysql.dbName]: Mysql
+}
diff --git a/test/helpers/Models/UserAvatarModel.js b/test/helpers/Models/UserAvatarModel.js
index 12021f1..423aebf 100644
--- a/test/helpers/Models/UserAvatarModel.js
+++ b/test/helpers/Models/UserAvatarModel.js
@@ -2,6 +2,7 @@ import { Model } from '../../../src'
 import './UserModel'
 
 export class UserAvatarModel extends Model {
+
 	static tableName = 'user_avatars'
 	static eager = '[user]'
 
@@ -9,7 +10,7 @@ export class UserAvatarModel extends Model {
 		type: 'object',
 
 		properties: {
-			id: { type: 'number' },
+			id: { type: 'integer' },
 			user_id: { type: 'integer', relation: 'user' },
 			url: { type: 'string', maxLength: 128 },
 			created_at: { type: 'string', format: 'date-time' },
@@ -22,4 +23,5 @@ export class UserAvatarModel extends Model {
 			user: this.belongsTo(UserModel)
 		}
 	}
+
 }
diff --git a/test/helpers/Models/UserModel.js b/test/helpers/Models/UserModel.js
index a9cf1c5..f9bdb73 100644
--- a/test/helpers/Models/UserModel.js
+++ b/test/helpers/Models/UserModel.js
@@ -2,6 +2,7 @@ import { Model } from '../../../src'
 import './UserAvatarModel'
 
 export class UserModel extends Model {
+
 	static tableName = 'users'
 
 	static buildRelations() {
diff --git a/test/helpers/makeApp.js b/test/helpers/makeApp.js
index 3d42e25..e04460e 100644
--- a/test/helpers/makeApp.js
+++ b/test/helpers/makeApp.js
@@ -3,16 +3,13 @@ require('babel-polyfill')
 import './Grind'
 import { DatabaseProvider } from 'grind-db'
 import { OrmProvider } from '../../src'
+import { Databases } from './Databases'
 
-const path = require('path')
-const crypto = require('crypto')
-const fs = require('fs')
-
-export async function makeApp(boot = () => { }) {
+export async function makeApp(dbName, boot = () => { }) {
 	const app = new Grind
-	const dbPath = path.join(__dirname, `../fixtures/database/database-${crypto.randomBytes(4).toString('hex')}.sqlite`)
 
-	app.config.set('database.connections.sqlite.filename', dbPath)
+	const db = Databases[dbName]
+	await db.ready(app)
 
 	app.providers.add(DatabaseProvider)
 	app.providers.add(OrmProvider)
@@ -20,17 +17,8 @@ export async function makeApp(boot = () => { }) {
 	await app.boot()
 	await boot()
 
-	await app.db.migrate.latest()
-	await app.db.seed.run()
-
-	app.on('shutdown', () => {
-		try {
-			// eslint-disable-next-line no-sync
-			fs.unlinkSync(dbPath)
-		} catch(err) {
-			Log.error('Unable to remove test db', err)
-		}
-	})
+	await db.runMigration(app)
+	app.on('shutdown', async () => db.shutdown(app))
 
 	return app
 }
diff --git a/test/helpers/test.js b/test/helpers/test.js
index f3890dc..bcacb1c 100644
--- a/test/helpers/test.js
+++ b/test/helpers/test.js
@@ -4,8 +4,7 @@ import '../helpers/Models/UserModel'
 import '../helpers/Models/UserAvatarModel'
 
 test.beforeEach(async t => {
-	t.context.app = await makeApp()
-
+	t.context.app = await makeApp(t.title.match(/\*(sqlite|mysql|pg)\*/)[1])
 	UserModel.app(t.context.app)
 	UserModel.knex(t.context.app.db)
 	t.context.UserModel = UserModel
@@ -17,6 +16,12 @@ test.beforeEach(async t => {
 
 test.afterEach.always(t => t.context.app.shutdown())
 
+export function testDBs(name, cb, dbs = [ 'sqlite', 'mysql', 'pg' ]) {
+	for(const db of dbs) {
+		test.serial(`*${db}*: ${name}`, cb)
+	}
+}
+
 module.exports = {
-	test: test.serial
+	test: testDBs
 }