Merge pull request #72 from crashtech/v2/schemas

Add support for multiple schemas

README.md

@@ -12,15 +12,14 @@
 * [TODO](https://github.com/crashtech/torque-postgresql/wiki/TODO)
 
 # Description
-`torque-postgresql` is a plugin that enhances Ruby on Rails enabling easy access to existing PostgreSQL advanced resources, such as data types and queries statements. Its features are designed to be as similar to Rails architecture and they work as smoothly as possible.
+`torque-postgresql` is a plugin that enhances Ruby on Rails enabling easy access to existing PostgreSQL advanced resources, such as data types and query statements. Its features are designed to be similar to Rails architecture and work as smoothly as possible.
 
-100% plug-and-play, with optional configurations, so that can be adapted to your project's design pattern.
+Fully compatible with `schema.rb` and 100% plug-and-play, with optional configurations, so that it can be adapted to your project's design pattern.
 
 # Installation
 
 To install torque-postgresql you need to add the following to your Gemfile:
 ```ruby
-gem 'torque-postgresql', '~> 1.1'   # For Rails  < 6.0
 gem 'torque-postgresql', '~> 2.0'   # For Rails >= 6.0 < 6.1
 gem 'torque-postgresql', '~> 2.0.4' # For Rails >= 6.1
 ```
@@ -48,25 +47,26 @@ These are the currently available features:
 
 ## Data types
 
+* [Box](https://github.com/crashtech/torque-postgresql/wiki/Box)
+* [Circle](https://github.com/crashtech/torque-postgresql/wiki/Circle)
+* [Date/Time Range](https://github.com/crashtech/torque-postgresql/wiki/Date-Time-Range)
 * [Enum](https://github.com/crashtech/torque-postgresql/wiki/Enum)
 * [EnumSet](https://github.com/crashtech/torque-postgresql/wiki/Enum-Set)
 * [Interval](https://github.com/crashtech/torque-postgresql/wiki/Interval)
-* [Date/Time Range](https://github.com/crashtech/torque-postgresql/wiki/Date-Time-Range)
-* [Box](https://github.com/crashtech/torque-postgresql/wiki/Box)
-* [Circle](https://github.com/crashtech/torque-postgresql/wiki/Circle)
 * [Line](https://github.com/crashtech/torque-postgresql/wiki/Line)
 * [Segment](https://github.com/crashtech/torque-postgresql/wiki/Segment)
 
 ## Querying
 
 * [Arel](https://github.com/crashtech/torque-postgresql/wiki/Arel)
-* [Has Many](https://github.com/crashtech/torque-postgresql/wiki/Has-Many)
+* [Auxiliary Statements](https://github.com/crashtech/torque-postgresql/wiki/Auxiliary-Statements)
 * [Belongs to Many](https://github.com/crashtech/torque-postgresql/wiki/Belongs-to-Many)
-* [Dynamic Attributes](https://github.com/crashtech/torque-postgresql/wiki/Dynamic-Attributes)
 * [Distinct On](https://github.com/crashtech/torque-postgresql/wiki/Distinct-On)
-* [Insert All](https://github.com/crashtech/torque-postgresql/wiki/Insert-All)
-* [Auxiliary Statements](https://github.com/crashtech/torque-postgresql/wiki/Auxiliary-Statements)
+* [Dynamic Attributes](https://github.com/crashtech/torque-postgresql/wiki/Dynamic-Attributes)
+* [Has Many](https://github.com/crashtech/torque-postgresql/wiki/Has-Many)
 * [Inherited Tables](https://github.com/crashtech/torque-postgresql/wiki/Inherited-Tables)
+* [Insert All](https://github.com/crashtech/torque-postgresql/wiki/Insert-All)
+* [Multiple Schemas](https://github.com/crashtech/torque-postgresql/wiki/Multiple-Schemas)
 
 # How to Contribute
 

README.rdoc

@@ -128,6 +128,23 @@ reconfigured on the model, and then can be used during querying process.
 
   {Learn more}[link:classes/Torque/PostgreSQL/AuxiliaryStatement.html]
 
+* Multiple Schemas
+
+Allows models and modules to have a schema associated with them, so that
+developers can better organize their tables into schemas and build features in
+a way that the database can better represent how they are separated.
+
+   create_schema "internal", force: :cascade
+
+   module Internal
+     class User < ActiveRecord::Base
+       self.schema = 'internal'
+     end
+   end
+
+   Internal::User.all
+
+  {Learn more}[link:classes/Torque/PostgreSQL/Adapter/DatabaseStatements.html]
 
 == Download and installation
 

lib/torque/postgresql.rb

@@ -20,12 +20,13 @@
 require 'torque/postgresql/attributes'
 require 'torque/postgresql/autosave_association'
 require 'torque/postgresql/auxiliary_statement'
-require 'torque/postgresql/base'
 require 'torque/postgresql/inheritance'
+require 'torque/postgresql/base'# Needs to be after inheritance
 require 'torque/postgresql/insert_all'
 require 'torque/postgresql/migration'
 require 'torque/postgresql/relation'
 require 'torque/postgresql/reflection'
 require 'torque/postgresql/schema_cache'
+require 'torque/postgresql/table_name'
 
 require 'torque/postgresql/railtie' if defined?(Rails)

lib/torque/postgresql/adapter.rb

@@ -31,9 +31,9 @@ def version
         )
       end
 
-      # Add `inherits` to the list of extracted table options
+      # Add `inherits` and `schema` to the list of extracted table options
       def extract_table_options!(options)
-        super.merge(options.extract!(:inherits))
+        super.merge(options.extract!(:inherits, :schema))
       end
 
       # Allow filtered bulk insert by adding the where clause. This method is

lib/torque/postgresql/adapter/database_statements.rb

@@ -12,6 +12,26 @@ def dump_mode!
           @_dump_mode = !!!@_dump_mode
         end
 
+        # List of schemas blocked by the application in the current connection
+        def schemas_blacklist
+          @schemas_blacklist ||= Torque::PostgreSQL.config.schemas.blacklist +
+            (@config.dig(:schemas, 'blacklist') || [])
+        end
+
+        # List of schemas used by the application in the current connection
+        def schemas_whitelist
+          @schemas_whitelist ||= Torque::PostgreSQL.config.schemas.whitelist +
+            (@config.dig(:schemas, 'whitelist') || [])
+        end
+
+        # A list of schemas on the search path sanitized
+        def schemas_search_path_sanitized
+          @schemas_search_path_sanitized ||= begin
+            db_user = @config[:username] || ENV['USER'] || ENV['USERNAME']
+            schema_search_path.split(',').map { |item| item.strip.sub('"$user"', db_user) }
+          end
+        end
+
         # Check if a given type is valid.
         def valid_type?(type)
           super || extended_types.include?(type)
@@ -22,6 +42,17 @@ def extended_types
           EXTENDED_DATABASE_TYPES
         end
 
+        # Checks if a given schema exists in the database. If +filtered+ is
+        # given as false, then it will check regardless of whitelist and
+        # blacklist
+        def schema_exists?(name, filtered: true)
+          return user_defined_schemas.include?(name.to_s) if filtered
+
+          query_value(<<-SQL) == 1
+            SELECT 1 FROM pg_catalog.pg_namespace WHERE nspname = '#{name}'
+          SQL
+        end
+
         # Returns true if type exists.
         def type_exists?(name)
           user_defined_types.key? name.to_s
@@ -115,18 +146,41 @@ def user_defined_types(*categories)
         # Get the list of inherited tables associated with their parent tables
         def inherited_tables
           tables = query(<<-SQL, 'SCHEMA')
-            SELECT child.relname             AS table_name,
-                   array_agg(parent.relname) AS inheritances
+            SELECT inhrelid::regclass  AS table_name,
+                   inhparent::regclass AS inheritances
             FROM pg_inherits
             JOIN pg_class parent ON pg_inherits.inhparent = parent.oid
             JOIN pg_class child  ON pg_inherits.inhrelid  = child.oid
-            GROUP BY child.relname, pg_inherits.inhrelid
-            ORDER BY pg_inherits.inhrelid
+            ORDER BY inhrelid
           SQL
 
-          tables.map do |(table, refs)|
-            [table, PG::TextDecoder::Array.new.decode(refs)]
-          end.to_h
+          tables.each_with_object({}) do |(child, parent), result|
+            (result[child] ||= []) << parent
+          end
+        end
+
+        # Get the list of schemas that were created by the user
+        def user_defined_schemas
+          query_values(user_defined_schemas_sql, 'SCHEMA')
+        end
+
+        # Build the query for allowed schemas
+        def user_defined_schemas_sql
+          conditions = []
+          conditions << <<-SQL if schemas_blacklist.any?
+            nspname NOT LIKE ANY (ARRAY['#{schemas_blacklist.join("', '")}'])
+          SQL
+
+          conditions << <<-SQL if schemas_whitelist.any?
+            nspname LIKE ANY (ARRAY['#{schemas_whitelist.join("', '")}'])
+          SQL
+
+          <<-SQL.squish
+            SELECT nspname
+            FROM pg_catalog.pg_namespace
+            WHERE 1=1 AND #{conditions.join(' AND ')}
+            ORDER BY oid
+          SQL
         end
 
         # Get the list of columns, and their definition, but only from the

lib/torque/postgresql/adapter/schema_dumper.rb

@@ -14,6 +14,7 @@ def dump(stream) # :nodoc:
 
         def extensions(stream) # :nodoc:
           super
+          user_defined_schemas(stream)
           user_defined_types(stream)
         end
 
@@ -41,7 +42,9 @@ def schema_enum_type(column)
 
           def tables(stream) # :nodoc:
             inherited_tables = @connection.inherited_tables
-            sorted_tables = @connection.tables.sort - @connection.views
+            sorted_tables = (@connection.tables - @connection.views).sort_by do |table_name|
+              table_name.split(/(?:public)?\./).reverse
+            end
 
             stream.puts "  # These are the common tables"
             (sorted_tables - inherited_tables.keys).each do |table_name|
@@ -58,7 +61,7 @@ def tables(stream) # :nodoc:
 
                 # Add the inherits setting
                 sub_stream.rewind
-                inherits.map!(&:to_sym)
+                inherits.map! { |parent| parent.to_s.sub(/\Apublic\./, '') }
                 inherits = inherits.first if inherits.size === 1
                 inherits = ", inherits: #{inherits.inspect} do |t|"
                 table_dump = sub_stream.read.gsub(/ do \|t\|$/, inherits)
@@ -84,6 +87,20 @@ def tables(stream) # :nodoc:
             triggers(stream) if defined?(::Fx::SchemaDumper::Trigger)
           end
 
+          # Make sure to remove the schema from the table name
+          def remove_prefix_and_suffix(table)
+            super(table.sub(/\A[a-z0-9_]*\./, ''))
+          end
+
+          # Dump user defined schemas
+          def user_defined_schemas(stream)
+            return if (list = (@connection.user_defined_schemas - ['public'])).empty?
+
+            stream.puts "  # Custom schemas defined in this database."
+            list.each { |name| stream.puts "  create_schema \"#{name}\", force: :cascade" }
+            stream.puts
+          end
+
           # Dump user defined types like enum
           def user_defined_types(stream)
             types = @connection.user_defined_types('e')

lib/torque/postgresql/adapter/schema_statements.rb

@@ -7,6 +7,21 @@ module SchemaStatements
 
         TableDefinition = ActiveRecord::ConnectionAdapters::PostgreSQL::TableDefinition
 
+        # Create a new schema
+        def create_schema(name, options = {})
+          drop_schema(name, options) if options[:force]
+
+          check = 'IF NOT EXISTS' if options.fetch(:check, true)
+          execute("CREATE SCHEMA #{check} #{quote_schema_name(name.to_s)}")
+        end
+
+        # Drop an existing schema
+        def drop_schema(name, options = {})
+          force = options.fetch(:force, '').upcase
+          check = 'IF EXISTS' if options.fetch(:check, true)
+          execute("DROP SCHEMA #{check} #{quote_schema_name(name.to_s)} #{force}")
+        end
+
         # Drops a type.
         def drop_type(name, options = {})
           force = options.fetch(:force, '').upcase
@@ -79,12 +94,37 @@ def enum_values(name)
 
         # Rewrite the method that creates tables to easily accept extra options
         def create_table(table_name, **options, &block)
+          table_name = "#{options[:schema]}.#{table_name}" if options[:schema].present?
+
           options[:id] = false if options[:inherits].present? &&
             options[:primary_key].blank? && options[:id].blank?
 
           super table_name, **options, &block
         end
 
+        # Add the schema option when extracting table options
+        def table_options(table_name)
+          parts = table_name.split('.').reverse
+          return super unless parts.size == 2 && parts[1] != 'public'
+
+          (super || {}).merge(schema: parts[1])
+        end
+
+        # When dumping the schema we need to add all schemas, not only those
+        # active for the current +schema_search_path+
+        def quoted_scope(name = nil, type: nil)
+          return super unless name.nil?
+
+          super.merge(schema: "ANY ('{#{user_defined_schemas.join(',')}}')")
+        end
+
+        # Fix the query to include the schema on tables names when dumping
+        def data_source_sql(name = nil, type: nil)
+          return super unless name.nil?
+
+          super.sub('SELECT c.relname FROM', "SELECT n.nspname || '.' || c.relname FROM")
+        end
+
         private
 
           def quote_enum_values(name, values, options)

lib/torque/postgresql/base.rb

@@ -5,15 +5,27 @@ module PostgreSQL
     module Base
       extend ActiveSupport::Concern
 
+      ##
+      # :singleton-method: schema
+      # :call-seq: schema
+      #
+      # The schema to which the table belongs to.
+
       included do
         mattr_accessor :belongs_to_many_required_by_default, instance_accessor: false
+        class_attribute :schema, instance_writer: false
       end
 
       module ClassMethods
         delegate :distinct_on, :with, :itself_only, :cast_records, to: :all
 
-        # Wenever it's inherited, add a new list of auxiliary statements
-        # It also adds an auxiliary statement to load inherited records' relname
+        # Make sure that table name is an instance of TableName class
+        def reset_table_name
+          self.table_name = TableName.new(self, super)
+        end
+
+        # Whenever the base model is inherited, add a list of auxiliary
+        # statements like the one that loads inherited records' relname
         def inherited(subclass)
           super
 
@@ -24,6 +36,11 @@ def inherited(subclass)
 
           # Define helper methods to return the class of the given records
           subclass.auxiliary_statement record_class do |cte|
+            ActiveSupport::Deprecation.warn(<<~MSG.squish)
+              Inheritance does not use this auxiliary statement and it can be removed.
+              You can replace it with `model.select_extra_values << 'tableoid::regclass'`.
+            MSG
+
             pg_class = ::Arel::Table.new('pg_class')
             arel_query = ::Arel::SelectManager.new(pg_class)
             arel_query.project(pg_class['oid'], pg_class['relname'].as(record_class.to_s))
@@ -36,18 +53,11 @@ def inherited(subclass)
           # Define the dynamic attribute that returns the same information as
           # the one provided by the auxiliary statement
           subclass.dynamic_attribute(record_class) do
-            next self.class.table_name unless self.class.physically_inheritances?
-
-            pg_class = ::Arel::Table.new('pg_class')
-            source = ::Arel::Table.new(subclass.table_name, as: 'source')
-            quoted_id = ::Arel::Nodes::Quoted.new(id)
-
-            query = ::Arel::SelectManager.new(pg_class)
-            query.join(source).on(pg_class['oid'].eq(source['tableoid']))
-            query.where(source[subclass.primary_key].eq(quoted_id))
-            query.project(pg_class['relname'])
+            klass = self.class
+            next klass.table_name unless klass.physically_inheritances?
 
-            self.class.connection.select_value(query)
+            query = klass.unscoped.where(subclass.primary_key => id)
+            query.pluck(klass.arel_table['tableoid'].cast('regclass')).first
           end
         end
 

lib/torque/postgresql/config.rb

@@ -40,6 +40,19 @@ def config.irregular_models=(hash)
       end.to_h
     end
 
+    # Configure multiple schemas
+    config.nested(:schemas) do |schemas|
+
+      # Defines a list of LIKE-based schemas to not consider for a multiple
+      # schema database
+      schemas.blacklist = %w[information_schema pg_%]
+
+      # Defines a list of LIKE-based schemas to consider for a multiple schema
+      # database
+      schemas.whitelist = %w[public]
+
+    end
+
     # Configure associations features
     config.nested(:associations) do |assoc|