sequelize case，关键点在于把事务 (transaction) t 传递到每一次数据库操作中

try {
  // get transaction
  transaction = await sequelize.transaction();

  await UserModel.create({ owner_id, email, password: sha256Password, password_salt, name, phone, address, level, remark, enable, sms_alarm_enable, email_alarm_enable }, { transaction });
  // step 1
  await Model.destroy({where: {id}, transaction});

  // step 2
  await Model.create({}, {transaction});

  // commit
  await transaction.commit();

} catch (err) {
  // Rollback transaction if any errors were encountered
  await transaction.rollback();
}

把conn作为参数传递到其他service函数就可以了 比如在service1中开启事务，调用service2中的函数

//service1 const conn = await this.app.mysql.beginTransaction(); try{

	await conn.insert(table, row1);
	await conn.update(table, row2);
	await this.ctx.service.service2.{method}(conn)
	await conn.commit();
	}catch(err){
	await conn.rollback()
	throw err;
	}

//service2 await conn.insert(table, row3);

用cls http://docs.sequelizejs.com/manual/tutorial/transactions.html#automatically-pass-transactions-to-all-queries