Add pg_eager_any_typed_array plugin, automatically transform eager lo…

…ads to use = ANY(array_expr::type[]) instead of IN (value_list)

This makes it easier to use the pg_auto_parameterize_in_array
extension with the :treat_string_list_as_text_array option, by
automatically using = ANY with the correct array type (instead
of Sequel assuming the text[] type, which may not be correct).

CHANGELOG

@@ -1,5 +1,7 @@
 === master
 
+* Add pg_eager_any_typed_array plugin, automatically transform eager loads to use = ANY(array_expr::type[]) instead of IN (value_list) (jeremyevans)
+
 * Support :eager_loading_predicate_transform association option (jeremyevans)
 
 * Support explicitly specifying :use_placeholder_loader association option (jeremyevans)

doc/testing.rdoc

@@ -192,6 +192,7 @@ SEQUEL_MODEL_THROW_FAILURES :: Use the throw_failures plugin when running the sp
 SEQUEL_NO_CACHE_ASSOCIATIONS :: Don't cache association metadata when running the specs
 SEQUEL_NO_PENDING :: Don't skip any specs, try running all specs (note, can cause lockups for some adapters)
 SEQUEL_PG_AUTO_PARAMETERIZE :: Use the pg_auto_parameterize extension when running the postgres specs.  Value can be +in_array+ to test the pg_auto_parameterize_in_array extension, and +in_array_string+ to test the pg_auto_parameterize_in_array extension with the +:treat_in_string_list_as_text_array+ Database option set.
+SEQUEL_PG_EAGER_ANY_TYPED_ARRAY :: Use the pg_eager_any_typed_array extension when running the postgres specs.
 SEQUEL_PG_TIMESTAMPTZ :: Use the pg_timestamptz extension when running the postgres specs
 SEQUEL_PRIMARY_KEY_LOOKUP_CHECK_VALUES :: Use the primary_key_lookup_check_values extension when running the adapter or integration specs
 SEQUEL_QUERY_PER_ASSOCIATION_DB_0_URL :: Run query-per-association integration tests with multiple databases (all 4 must be set to run)

lib/sequel/plugins/pg_eager_any_typed_array.rb

@@ -0,0 +1,66 @@
+# frozen-string-literal: true
+
+module Sequel
+  module Plugins
+    # The pg_eager_any_typed_array plugin automatically converts
+    # the predicate expressions used for eager loading from:
+    #
+    #   table.column IN (value_list)
+    #
+    # to:
+    #
+    #   table.column = ANY(array_expr::type[])
+    #
+    # This makes it easier to use the pg_auto_parameterize_in_array
+    # extension with the :treat_string_list_as_text_array option,
+    # when using foreign keys with non-text database types that are represented
+    # by Ruby strings, such as enum and uuid types.
+    #
+    # To avoid this behavior for particular associations, set the
+    # :eager_loading_predicate_transform association option to nil/false.
+    #
+    # This plugin loads the pg_array extension into the model's Database.
+    module PgEagerAnyTypedArray
+      # Add the pg_array extension to the database
+      def self.apply(model)
+        model.db.extension(:pg_array)
+      end
+
+      module ClassMethods
+        TRANSFORM = proc do |values, ref|
+          type = ref.send(:cached_fetch, :_pg_eager_any_typed_array_type) do
+            key = ref.predicate_key
+            next if key.is_a?(Array)
+
+            while key.is_a?(SQL::QualifiedIdentifier)
+              key = key.column
+            end
+
+            if (sch = ref.associated_class.db_schema[key])
+              sch[:db_type]
+            end
+          end
+
+          if type
+            Sequel.function(:ANY, Sequel.pg_array(values, type))
+          else
+            values
+          end
+        end
+
+        # If the association does not use a composite predicate key,
+        # and does not already have the :eager_loading_predicate_transform
+        # option set, set the option so that eager loading
+        def associate(type, name, opts = OPTS, &block)
+          res = super
+
+          unless res.has_key?(:eager_loading_predicate_transform)
+            res[:eager_loading_predicate_transform] = TRANSFORM
+          end
+
+          res
+        end
+      end
+    end
+  end
+end

spec/adapters/spec_helper.rb

@@ -41,6 +41,7 @@
 
 IDENTIFIER_MANGLING = !!ENV['SEQUEL_IDENTIFIER_MANGLING'] unless defined?(IDENTIFIER_MANGLING)
 DB.extension(:identifier_mangling) if IDENTIFIER_MANGLING
+Sequel::Model.plugin :pg_eager_any_typed_array if ENV['SEQUEL_PG_EAGER_ANY_TYPED_ARRAY']
 
 if DB.adapter_scheme == :ibmdb || (DB.adapter_scheme == :ado && DB.database_type == :access)
   def DB.drop_table(*tables)

spec/extensions/pg_eager_any_typed_array_spec.rb

@@ -0,0 +1,48 @@
+require File.join(File.dirname(File.expand_path(__FILE__)), "spec_helper")
+
+describe "pg_eager_any_typed_array plugin" do
+  before do
+    @db = Sequel.connect('mock://postgres')
+    @c = Class.new(Sequel::Model(@db[:items]))
+    def @c.name; "C" end
+    @c.columns :id, :c_id
+    @c.plugin :pg_eager_any_typed_array
+    @c.dataset = @c.dataset.with_fetch([[{:id=>1, :c_id=>2}, {:id=>3, :c_id=>4}]])
+    @c.db_schema[:id][:db_type] = "int4"
+    @c.db_schema[:c_id][:db_type] = "int8"
+    @c.one_to_many :cs, :class=>@c
+    @c.many_to_one :c, :class=>@c
+    @c.many_to_one :cc, :class=>@c, :key=>[:id, :c_id], :primary_key=>[:id, :c_id]
+    @db.sqls
+  end
+
+  it "should automatically use column = ANY() for eager loads using scaler keys with known type" do
+    @c.eager(:c, :cs).all
+    @db.sqls.must_equal ['SELECT * FROM "items"',
+      'SELECT * FROM "items" WHERE ("items"."id" = ANY(ARRAY[2,4]::int4[]))',
+      'SELECT * FROM "items" WHERE ("items"."c_id" = ANY(ARRAY[1,3]::int8[]))']
+  end
+
+  it "should automatically use (column1, column2) IN (value_list) for eager loads using composite keys" do
+    @c.eager(:cc).all
+    @db.sqls.must_equal ['SELECT * FROM "items"', 'SELECT * FROM "items" WHERE (("items"."id", "items"."c_id") IN ((1, 2), (3, 4)))']
+  end
+
+  it "should automatically use column IN (value_list) for eager loads using scalar keys with unknown type" do
+    @c.db_schema[:id].delete(:db_type)
+    @c.db_schema[:c_id].delete(:db_type)
+    @c.eager(:c, :cs).all
+    @db.sqls.must_equal ['SELECT * FROM "items"',
+      'SELECT * FROM "items" WHERE ("items"."id" IN (2, 4))',
+      'SELECT * FROM "items" WHERE ("items"."c_id" IN (1, 3))']
+  end
+
+  it "should automatically use column IN (value_list) for eager loads when explicitly disabled" do
+    @c.one_to_many :cs, :class=>@c, :eager_loading_predicate_transform=>nil
+    @c.many_to_one :c, :class=>@c, :eager_loading_predicate_transform=>nil
+    @c.eager(:c, :cs).all
+    @db.sqls.must_equal ['SELECT * FROM "items"',
+      'SELECT * FROM "items" WHERE ("items"."id" IN (2, 4))',
+      'SELECT * FROM "items" WHERE ("items"."c_id" IN (1, 3))']
+  end
+end

www/pages/plugins.html.erb

@@ -110,6 +110,10 @@
 <span class="ul__span">Adds associations types to handle the case where foreign keys are stored in a PostgreSQL array in one of the tables.</span>
 </li>
 <li class="ul__li ul__li--grid">
+<a class="a" href="rdoc-plugins/classes/Sequel/Plugins/PgEagerAnyTypedArray.html">pg_eager_any_typed_array</a>
+<span class="ul__span">Makes eager loading predicates use <code>key = ANY(array_expr::type[])</code> instead of <code>key IN (value_list)</code>.</span>
+</li>
+<li class="ul__li ul__li--grid">
 <a class="a" href="rdoc-plugins/classes/Sequel/Plugins/RcteTree.html">rcte_tree </a>
 <span class="ul__span">Supports retrieving all ancestors and descendants for tree structured data using recursive common table expressions.</span>
 </li>