use an array for bind params to simplify substitution

activerecord/lib/active_record/core.rb

@@ -136,10 +136,10 @@ module ActiveRecord
 
         s = find_by_statement_cache[key] || find_by_statement_cache.synchronize {
           find_by_statement_cache[key] ||= StatementCache.create(connection) { |params|
-            where(key => params[key]).limit(1)
+            where(key => params.bind).limit(1)
           }
         }
-        record = s.execute({key => id}, self, connection).first
+        record = s.execute([id], self, connection).first
         unless record
           raise RecordNotFound, "Couldn't find #{name} with '#{primary_key}'=#{id}"
         end
@@ -161,13 +161,13 @@ module ActiveRecord
         s = find_by_statement_cache[key] || find_by_statement_cache.synchronize {
           find_by_statement_cache[key] ||= StatementCache.create(connection) { |params|
             wheres = key.each_with_object({}) { |param,o|
-              o[param] = params[param]
+              o[param] = params.bind
             }
             klass.where(wheres).limit(1)
           }
         }
         begin
-          s.execute(hash, self, connection).first
+          s.execute(hash.values, self, connection).first
         rescue TypeError => e
           raise ActiveRecord::StatementInvalid.new(e.message, e)
         end

activerecord/lib/active_record/statement_cache.rb

@@ -14,7 +14,7 @@ module ActiveRecord
   # The relation returned by the block is cached, and for each +execute+ call the cached relation gets duped.
   # Database is queried when +to_a+ is called on the relation.
   class StatementCache
-    Substitute = Struct.new :name
+    class Substitute; end
 
     class Query
       def initialize(sql)
@@ -52,24 +52,24 @@ module ActiveRecord
     end
 
     class Params
-      def [](name); Substitute.new name; end
+      def bind; Substitute.new; end
     end
 
     class BindMap
       def initialize(bind_values)
-        @value_map   = {}
+        @indexes   = []
         @bind_values = bind_values
 
         bind_values.each_with_index do |(_, value), i|
           if Substitute === value
-            @value_map[value.name] = i
+            @indexes << i
           end
         end
       end
 
       def bind(values)
         bvs = @bind_values.map { |pair| pair.dup }
-        values.each { |k,v| bvs[@value_map[k]][1] = v }
+        @indexes.each_with_index { |offset,i| bvs[offset][1] = values[i] }
         bvs
       end
     end

activerecord/test/cases/statement_cache_test.rb

@@ -16,12 +16,12 @@ module ActiveRecord
       Book.create(name: "my other book")
 
       cache = StatementCache.create(Book.connection) do |params|
-        Book.where(:name => params[:name])
+        Book.where(:name => params.bind)
       end
 
-      b = cache.execute({ name: "my book" }, Book, Book.connection)
+      b = cache.execute([ "my book" ], Book, Book.connection)
       assert_equal "my book", b[0].name
-      b = cache.execute({ name: "my other book" }, Book, Book.connection)
+      b = cache.execute([ "my other book" ], Book, Book.connection)
       assert_equal "my other book", b[0].name
     end
 
@@ -31,12 +31,12 @@ module ActiveRecord
       b2 = Book.create(name: "my other book")
 
       cache = StatementCache.create(Book.connection) do |params|
-        Book.where(id: params[:id])
+        Book.where(id: params.bind)
       end
 
-      b = cache.execute({ id: b1.id }, Book, Book.connection)
+      b = cache.execute([ b1.id ], Book, Book.connection)
       assert_equal b1.name, b[0].name
-      b = cache.execute({ id: b2.id }, Book, Book.connection)
+      b = cache.execute([ b2.id ], Book, Book.connection)
       assert_equal b2.name, b[0].name
     end
 
@@ -59,7 +59,7 @@ module ActiveRecord
 
       Book.create(name: "my book", author_id: 4)
 
-      books = cache.execute({}, Book, Book.connection)
+      books = cache.execute([], Book, Book.connection)
       assert_equal "my book", books[0].name
     end
 
@@ -72,7 +72,7 @@ module ActiveRecord
       molecule = salty.molecules.create(name: 'dioxane')
       molecule.electrons.create(name: 'lepton')
 
-      liquids = cache.execute({}, Book, Book.connection)
+      liquids = cache.execute([], Book, Book.connection)
       assert_equal "salty", liquids[0].name
     end
 
@@ -85,13 +85,13 @@ module ActiveRecord
         Book.create(name: "my book")
       end
 
-      first_books = cache.execute({}, Book, Book.connection)
+      first_books = cache.execute([], Book, Book.connection)
 
       3.times do
         Book.create(name: "my book")
       end
 
-      additional_books = cache.execute({}, Book, Book.connection)
+      additional_books = cache.execute([], Book, Book.connection)
       assert first_books != additional_books
     end
   end