multi-tenancy

class Document < ApplicationRecord
  belongs_to :owner, class_name: "User"
  has_many :visibilities, class_name: "DocumentVisibility", dependent: :delete_all

  scope :public_documents, -> { where(is_public: true) }

-- Pattern 1: Shared schema with tenant_id column

CREATE TABLE tenants (
  id SERIAL PRIMARY KEY,
  name VARCHAR(100) NOT NULL,
  slug VARCHAR(50) UNIQUE NOT NULL,

Apartment.configure do |config|
  config.excluded_models = %w[Tenant User]
  config.tenant_names = -> { Tenant.pluck(:schema_name) }
  config.use_schemas = true
end

<?php

namespace App\Scopes;

use Illuminate\Database\Eloquent\Builder;
use Illuminate\Database\Eloquent\Model;

class Comment < ApplicationRecord
  belongs_to :account
  belongs_to :author, class_name: "User"

  validates :body, presence: true

import threading
from contextlib import contextmanager

_state = threading.local()

<?php

namespace App\Models\Scopes;

use App\Support\TenantContext;
use Illuminate\Database\Eloquent\Builder;

class Current < ActiveSupport::CurrentAttributes
  attribute :tenant, :request_id

  def tenant=(tenant)
    super
    Rails.logger.tagged("tenant=#{tenant&.id}") if tenant

package com.example.demo.multitenancy;

public class TenantContext {
    private static final ThreadLocal<String> CURRENT_TENANT = new ThreadLocal<>();

    public static void setTenantId(String tenantId) {