Make insert_returning_select use RETURNING when using table_select plugin

This changes insert_returning_select to handle SELECT table.* and use RETURNING * for the INSERT. Previously, insert_returning_select only handled explicit column selections, such as those created by the column_select plugin.

Author: jeremyevans

CHANGELOG

@@ -1,5 +1,7 @@
 === master
 
+* Make insert_returning_select use RETURNING when using table_select plugin (jeremyevans) (#2339)
+
 * Fix Database#listen in postgres adapter to ignore all notifications after UNLISTEN (jeremyevans)
 
 * Make Model.any? forward to the dataset, to work better with the any_not_empty extension (jeremyevans) (#2337)

lib/sequel/plugins/insert_returning_select.rb

@@ -2,7 +2,7 @@
 
 module Sequel
  module Plugins
- # If the model's dataset selects explicit columns and the
+ # If the model's dataset selects explicit columns (or table.*) and the
  # database supports it, the insert_returning_select plugin will
  # automatically set the RETURNING clause on the dataset used to
  # insert rows to the columns selected, which allows the default model
@@ -45,13 +45,22 @@ def reset_instance_dataset
  ret
  end
 
+ RETURN_ALL = [Sequel::Dataset::WILDCARD].freeze
+ private_constant :RETURN_ALL
+
  # Determine the columns to use for the returning clause, or return nil
  # if they can't be determined and a returning clause should not be
  # added automatically.
  def insert_returning_columns(ds)
  return unless ds.supports_returning?(:insert)
  return unless values = ds.opts[:select]
 
+ # SELECT table.* -> RETURNING *
+ if values.length == 1 && values[0].is_a?(Sequel::SQL::ColumnAll)
+ return RETURN_ALL
+ end
+
+ # SELECT column1, table.column2, ... -> RETURNING column1, column2, ...
  values = values.map{|v| ds.unqualified_column_for(v)}
  if values.all?
  values

lib/sequel/plugins/table_select.rb

@@ -9,6 +9,13 @@ module Plugins
  # in the result sets (and possibly overwrite columns in the
  # current model with the same name).
  #
+ # Note that by default on databases that supporting RETURNING,
+ # using this plugin will cause instance creations
+ # to use two queries (insert and refresh) instead of a single
+ # query using RETURNING. You can use the insert_returning_select
+ # plugin to automatically use RETURNING for instance creations
+ # for models using this plugin.
+ #
  # Usage:
  #
  # # Make all model subclasses select table.*

spec/extensions/insert_returning_select_spec.rb

@@ -38,6 +38,16 @@ def insert_select(*v) with_sql_first("#{insert_sql(*v)}#{" RETURNING #{opts[:ret
  @db.sqls.must_equal ['INSERT INTO albums (x) VALUES (2) RETURNING id, x']
  end
 
+ it "should add a returning clause when dataset selects all columns from a single table" do
+ @Album = Class.new(Sequel::Model(@db[:albums]))
+ @Album.columns :id, :x
+ @Album.plugin :table_select
+ @Album.plugin :insert_returning_select
+ @db.sqls
+ @Album.create(:x=>2).must_equal @Album.load(:id=>1, :x=>2)
+ @db.sqls.must_equal ['INSERT INTO albums (x) VALUES (2) RETURNING *']
+ end
+
  it "should not add a returning clause if no columns are selected" do
  @Album.plugin :insert_returning_select
  @Album.dataset = @Album.dataset.select_all