1 files changed, 24 insertions, 0 deletions
diff --git a/activerecord/lib/arel/nodes/extract.rb b/activerecord/lib/arel/nodes/extract.rb
new file mode 100644
index 0000000000..5799ee9b8f
--- /dev/null
+++ b/activerecord/lib/arel/nodes/extract.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+module Arel # :nodoc: all
+  module Nodes
+    class Extract < Arel::Nodes::Unary
+      attr_accessor :field
+
+      def initialize(expr, field)
+        super(expr)
+        @field = field
+      end
+
+      def hash
+        super ^ @field.hash
+      end
+
+      def eql?(other)
+        super &&
+          self.field == other.field
+      end
+      alias :== :eql?
+    end
+  end
+end