""" Django management command to migrate from tenant-filtered approach to schema separation. This command: 1. Creates separate PostgreSQL schemas for each tenant 2. Migrates existing data from the default schema to tenant-specific schemas 3. Handles all models: Customer, Product, Category, Sale, etc. """ from django.core.management.base import BaseCommand from django.db import connection from tenants.models import Tenant from tenants.schema_utils import ( get_tenant_schema_name, create_tenant_schema, schema_exists, SchemaManager ) import logging logger = logging.getLogger(__name__) class Command(BaseCommand): help = 'Migrate from tenant-filtered approach to PostgreSQL schema separation' def add_arguments(self, parser): parser.add_argument( '--dry-run', action='store_true', help='Show what would be done without actually doing it', ) parser.add_argument( '--force', action='store_true', help='Force migration even if schemas already exist', ) def handle(self, *args, **options): dry_run = options['dry_run'] force = options['force'] if dry_run: self.stdout.write( self.style.WARNING('DRY RUN MODE - No changes will be made') ) # Get all tenants tenants = Tenant.objects.all() if not tenants.exists(): self.stdout.write( self.style.ERROR('No tenants found. Create a tenant first.') ) return self.stdout.write(f'Found {tenants.count()} tenant(s) to migrate') for tenant in tenants: self.migrate_tenant(tenant, dry_run, force) self.stdout.write( self.style.SUCCESS('Schema separation migration completed!') ) def migrate_tenant(self, tenant, dry_run=False, force=False): """Migrate a single tenant to its own schema""" schema_name = get_tenant_schema_name(tenant.tenant_code) self.stdout.write(f'\n=== Migrating tenant: {tenant.name} (code: {tenant.tenant_code}) ===') self.stdout.write(f'Target schema: {schema_name}') if not dry_run: # Create the tenant schema try: created = create_tenant_schema(tenant.tenant_code) if created: self.stdout.write( self.style.SUCCESS(f'✓ Created schema: {schema_name}') ) else: if force: self.stdout.write( self.style.WARNING(f'⚠ Schema {schema_name} already exists (continuing due to --force)') ) else: self.stdout.write( self.style.ERROR(f'✗ Schema {schema_name} already exists. Use --force to continue.') ) return # Exit this tenant migration except Exception as e: self.stdout.write( self.style.ERROR(f'✗ Failed to create schema {schema_name}: {e}') ) return # Exit this tenant migration # Migrate data for each app/model self.migrate_tenant_data(tenant, schema_name, dry_run) def migrate_tenant_data(self, tenant, schema_name, dry_run=False): """Migrate tenant data from default schema to tenant schema""" # Models to migrate with their table names models_to_migrate = [ ('customers', 'customers_customer'), ('inventory', 'inventory_category'), ('inventory', 'inventory_product'), ('inventory', 'inventory_productimage'), ('inventory', 'inventory_batch'), ('sales', 'sales_sale'), ('sales', 'sales_saleitem'), ('sales', 'sales_salepayment'), # Add other models as needed ] with connection.cursor() as cursor: for app_name, table_name in models_to_migrate: try: # Check if table exists in default schema cursor.execute(""" SELECT EXISTS ( SELECT 1 FROM information_schema.tables WHERE table_schema = 'public' AND table_name = %s ) """, [table_name]) table_exists = cursor.fetchone()[0] if not table_exists: self.stdout.write(f' - Skipping {table_name} (table not found)') continue # Check if table has tenant field (for old data) cursor.execute(""" SELECT column_name FROM information_schema.columns WHERE table_schema = 'public' AND table_name = %s AND column_name = 'tenant_id' """, [table_name]) has_tenant_field = cursor.fetchone() is not None if has_tenant_field: # Migrate tenant-filtered data self.migrate_filtered_data(cursor, tenant, table_name, schema_name, dry_run) else: # Migrate all data (for models that never had tenant fields) self.migrate_all_data(cursor, table_name, schema_name, dry_run) except Exception as e: self.stdout.write( self.style.ERROR(f' ✗ Error migrating {table_name}: {e}') ) def migrate_filtered_data(self, cursor, tenant, table_name, schema_name, dry_run=False): """Migrate data filtered by tenant_id""" # Count records for this tenant cursor.execute(f""" SELECT COUNT(*) FROM public.{table_name} WHERE tenant_id = %s """, [tenant.id]) count = cursor.fetchone()[0] if count == 0: self.stdout.write(f' - {table_name}: No records to migrate') return if dry_run: self.stdout.write(f' - {table_name}: Would migrate {count} records') return # Copy tenant data to new schema (excluding tenant_id field) cursor.execute(f""" SELECT column_name FROM information_schema.columns WHERE table_schema = 'public' AND table_name = %s AND column_name != 'tenant_id' ORDER BY ordinal_position """, [table_name]) columns = [row[0] for row in cursor.fetchall()] columns_str = ', '.join(columns) try: cursor.execute(f""" INSERT INTO {schema_name}.{table_name} ({columns_str}) SELECT {columns_str} FROM public.{table_name} WHERE tenant_id = %s """, [tenant.id]) self.stdout.write(f' ✓ {table_name}: Migrated {count} records') except Exception as e: self.stdout.write(f' ✗ {table_name}: Migration failed - {e}') def migrate_all_data(self, cursor, table_name, schema_name, dry_run=False): """Migrate all data (for models without tenant filtering)""" # Count all records cursor.execute(f"SELECT COUNT(*) FROM public.{table_name}") count = cursor.fetchone()[0] if count == 0: self.stdout.write(f' - {table_name}: No records to migrate') return if dry_run: self.stdout.write(f' - {table_name}: Would migrate {count} records') return # Copy all data to new schema try: cursor.execute(f""" INSERT INTO {schema_name}.{table_name} SELECT * FROM public.{table_name} """) self.stdout.write(f' ✓ {table_name}: Migrated {count} records') except Exception as e: self.stdout.write(f' ✗ {table_name}: Migration failed - {e}')