Stop using `Arel::Table.engine`

We never actually make use of it on the table, since we're constructing
the select manager manually. It looks like if we ever actually were
grabbing it from the table, we're grossly misusing it since it's meant
to vary by AR class.

Its existence on `Arel::Table` appears to be purely for convenience
methods that are never used outside of tests. However, in production
code it just complicates construction of the tables on the rails side,
and the plan is to remove it from `Arel::Table` entirely. I'm not
convinced it needs to live on `SelectManager`, etc either.

4 files changed, 5 insertions, 5 deletions

diff --git a/activerecord/lib/active_record/core.rb b/activerecord/lib/active_record/core.rb
index 89d8932e9e..c812e7842a 100644
--- a/activerecord/lib/active_record/core.rb
+++ b/activerecord/lib/active_record/core.rb
@@ -235,7 +235,7 @@ module ActiveRecord
       #     scope :published_and_commented, -> { published.and(self.arel_table[:comments_count].gt(0)) }
       #   end
       def arel_table # :nodoc:
-        @arel_table ||= Arel::Table.new(table_name, arel_engine)
+        @arel_table ||= Arel::Table.new(table_name)
       end
 
       # Returns the Arel engine.
diff --git a/activerecord/lib/active_record/relation/predicate_builder.rb b/activerecord/lib/active_record/relation/predicate_builder.rb
index e4b6b49087..938bf55c6d 100644
--- a/activerecord/lib/active_record/relation/predicate_builder.rb
+++ b/activerecord/lib/active_record/relation/predicate_builder.rb
@@ -25,7 +25,7 @@ module ActiveRecord
           if value.empty?
             queries << '1=0'
           else
-            table       = Arel::Table.new(column, default_table.engine)
+            table       = Arel::Table.new(column)
             association = klass._reflect_on_association(column)
 
             value.each do |k, v|
@@ -37,7 +37,7 @@ module ActiveRecord
 
           if column.include?('.')
             table_name, column = column.split('.', 2)
-            table = Arel::Table.new(table_name, default_table.engine)
+            table = Arel::Table.new(table_name)
           end
 
           queries.concat expand(klass, table, column, value)
diff --git a/activerecord/lib/active_record/relation/query_methods.rb b/activerecord/lib/active_record/relation/query_methods.rb
index 6e384facce..0edd2b1e48 100644
--- a/activerecord/lib/active_record/relation/query_methods.rb
+++ b/activerecord/lib/active_record/relation/query_methods.rb
@@ -858,7 +858,7 @@ module ActiveRecord
     private
 
     def build_arel
-      arel = Arel::SelectManager.new(table.engine, table)
+      arel = Arel::SelectManager.new(klass.arel_engine, table)
 
       build_joins(arel, joins_values.flatten) unless joins_values.empty?
 
diff --git a/activerecord/lib/active_record/sanitization.rb b/activerecord/lib/active_record/sanitization.rb
index 6a130c145b..88dfddebcc 100644
--- a/activerecord/lib/active_record/sanitization.rb
+++ b/activerecord/lib/active_record/sanitization.rb
@@ -93,7 +93,7 @@ sanitize_sql_hash_for_conditions is deprecated, and will be removed in Rails 5.0
         attrs = PredicateBuilder.resolve_column_aliases self, attrs
         attrs = expand_hash_conditions_for_aggregates(attrs)
 
-        table = Arel::Table.new(table_name, arel_engine).alias(default_table_name)
+        table = Arel::Table.new(table_name).alias(default_table_name)
         PredicateBuilder.build_from_hash(self, attrs, table).map { |b|
           connection.visitor.compile b
         }.join(' AND ')