lib/rom/sql/relation.rb in rom-sql-0.7.0 vs lib/rom/sql/relation.rb in rom-sql-0.8.0

@@ -1,21 +1,30 @@
 require 'rom/sql/header'
+require 'rom/sql/types'
 
+require 'rom/sql/schema'
+
 require 'rom/sql/relation/reading'
 require 'rom/sql/relation/writing'
 
 require 'rom/plugins/relation/view'
 require 'rom/plugins/relation/key_inference'
 require 'rom/plugins/relation/sql/base_view'
 require 'rom/plugins/relation/sql/auto_combine'
 require 'rom/plugins/relation/sql/auto_wrap'
 
+require 'rom/support/deprecations'
+require 'rom/support/constants'
+
 module ROM
   module SQL
     # Sequel-specific relation extensions
     #
+    # @api public
     class Relation < ROM::Relation
+      include SQL
+
       adapter :sql
 
       use :key_inference
       use :view
       use :base_view
@@ -23,74 +32,116 @@
       use :auto_wrap
 
       include Writing
       include Reading
 
-      # @attr_reader [Header] header Internal lazy-initialized header
-      attr_reader :header
-
-      # Name of the table used in FROM clause
-      #
-      # @attr_reader [Symbol] table
-      attr_reader :table
-
       # Set default dataset for a relation sub-class
       #
       # @api private
       def self.inherited(klass)
         super
 
         klass.class_eval do
+          schema_dsl SQL::Schema::DSL
+          schema_inferrer ROM::SQL::Schema::Inferrer
+
           dataset do
             table = opts[:from].first
 
             if db.table_exists?(table)
-              # quick fix for dbs w/o primary_key inference
-              #
-              # TODO: add a way of setting a pk explicitly on a relation
-              pk =
-                if db.respond_to?(:primary_key)
-                  Array(db.primary_key(table))
-                else
-                  [:id]
-                end.map { |name| :"#{table}__#{name}" }
-
-                select(*columns).order(*pk)
+              pk_header = klass.primary_key_header(db, table)
+              select(*columns).order(*pk_header.qualified)
             else
               self
             end
           end
+
+          # @!method by_pk(pk)
+          #   Return a relation restricted by its primary key
+          #   @param [Object] pk The primary key value
+          #   @return [SQL::Relation]
+          #   @api public
+          view(:by_pk, attributes[:base]) do |pk|
+            where(primary_key => pk)
+          end
         end
       end
 
+      # @api private
+      def self.associations
+        schema.associations
+      end
+
+      # @api private
+      def self.primary_key_header(db, table)
+        names =
+          if schema
+            schema.primary_key_names
+          elsif db.respond_to?(:primary_key)
+            Array(db.primary_key(table))
+          else
+            [:id]
+          end
+        Header.new(names, table)
+      end
+
+      # Set primary key
+      #
+      # @deprecated
+      #
+      # @api public
       def self.primary_key(value)
+        Deprecations.announce(
+          :primary_key, "use schema definition to configure primary key"
+        )
         option :primary_key, reader: true, default: value
       end
 
-      primary_key :id
+      option :primary_key, reader: true, default: -> rel {
+        rel.schema? ? rel.schema.primary_key_name : :id
+      }
 
+      # Return table name from relation's sql statement
+      #
+      # This value is used by `header` for prefixing column names
+      #
+      # @return [Symbol]
+      #
       # @api private
-      def initialize(dataset, registry = {})
-        super
-        @table = dataset.opts[:from].first
+      def table
+        @table ||= dataset.opts[:from].first
       end
 
       # Return a header for this relation
       #
       # @return [Header]
       #
       # @api private
       def header
-        @header ||= Header.new(dataset.opts[:select] || dataset.columns, table)
+        @header ||= Header.new(selected_columns, table)
       end
 
       # Return raw column names
       #
       # @return [Array<Symbol>]
       #
       # @api private
       def columns
-        dataset.columns
+        @columns ||= dataset.columns
+      end
+
+      protected
+
+      # Return a list of columns from *the sql select* statement or default to
+      # dataset columns
+      #
+      # This is used to construct relation's header
+      #
+      # @return [Array<Symbol>]
+      #
+      # @api private
+      def selected_columns
+        @selected_columns ||= dataset.opts.fetch(:select, columns)
       end
     end
   end
 end