Allow a list of schemas when switching using schemas

README.md

@@ -101,6 +101,16 @@ switched back at the end of the block to what it was before.
 There is also `switch!` which doesn't take a block, but it's recommended to use `switch`.
 To return to the default tenant, you can call `switch` with no arguments.
 
+#### Multiple Tenants
+
+When using schemas, you can also pass in a list of schemas if desired. Any tables defined in a schema earlier in the chain will be referenced first, so this is only useful if you have a schema with only some of the tables defined:
+
+```ruby
+Apartment::Tenant.switch(['tenant_1', 'tenant_2']) do
+  # ...
+end
+```
+
 ### Switching Tenants per request
 
 You can have Apartment route to the appropriate tenant by adding some Rack middleware.

lib/apartment/adapters/jdbc_postgresql_adapter.rb

@@ -38,11 +38,9 @@ class JDBCPostgresqlSchemaAdapter < PostgresqlSchemaAdapter
       #
       def connect_to_new(tenant = nil)
         return reset if tenant.nil?
+        raise ActiveRecord::StatementInvalid, "Could not find schema #{tenant}" unless schema_exists?(tenant)
 
-        tenant = tenant.to_s
-        raise ActiveRecord::StatementInvalid, "Could not find schema #{tenant}" unless tenant_exists?(tenant)
-
-        @current = tenant
+        @current = tenant.is_a?(Array) ? tenant.map(&:to_s) : tenant.to_s
         Apartment.connection.schema_search_path = full_search_path
       rescue ActiveRecord::StatementInvalid, ActiveRecord::JDBCError
         raise TenantNotFound, "One of the following schema(s) is invalid: #{full_search_path}"

lib/apartment/adapters/postgresql_adapter.rb

@@ -72,11 +72,9 @@ def drop_command(conn, tenant)
       #
       def connect_to_new(tenant = nil)
         return reset if tenant.nil?
+        raise ActiveRecord::StatementInvalid, "Could not find schema #{tenant}" unless schema_exists?(tenant)
 
-        tenant = tenant.to_s
-        raise ActiveRecord::StatementInvalid, "Could not find schema #{tenant}" unless tenant_exists?(tenant)
-
-        @current = tenant
+        @current = tenant.is_a?(Array) ? tenant.map(&:to_s) : tenant.to_s
         Apartment.connection.schema_search_path = full_search_path
 
         # When the PostgreSQL version is < 9.3,
@@ -149,6 +147,12 @@ def reset_sequence_names
           c.remove_instance_variable :@sequence_name if c.instance_variable_defined?(:@sequence_name)
         end
       end
+
+      def schema_exists?(schemas)
+        return true unless Apartment.tenant_presence_check
+
+        [*schemas].all? { |schema| Apartment.connection.schema_exists?(schema.to_s) }
+      end
     end
 
     # Another Adapter for Postgresql when using schemas and SQL

spec/examples/schema_adapter_examples.rb

@@ -127,6 +127,13 @@
       expect(connection.schema_search_path).to start_with %("#{public_schema}")
       expect(User.sequence_name).to eq "#{public_schema}.#{User.table_name}_id_seq"
     end
+
+    it "allows a list of schemas" do
+      subject.switch([schema1, schema2]) do
+        expect(connection.schema_search_path).to include %{"#{schema1}"}
+        expect(connection.schema_search_path).to include %{"#{schema2}"}
+      end
+    end
   end
 
   describe '#reset' do