1 files changed, 29 insertions, 0 deletions
diff --git a/activerecord/lib/arel/expressions.rb b/activerecord/lib/arel/expressions.rb
new file mode 100644
index 0000000000..612a0942f1
--- /dev/null
+++ b/activerecord/lib/arel/expressions.rb
@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+module Arel
+  module Expressions
+    def count distinct = false
+      Nodes::Count.new [self], distinct
+    end
+
+    def sum
+      Nodes::Sum.new [self]
+    end
+
+    def maximum
+      Nodes::Max.new [self]
+    end
+
+    def minimum
+      Nodes::Min.new [self]
+    end
+
+    def average
+      Nodes::Avg.new [self]
+    end
+
+    def extract field
+      Nodes::Extract.new [self], field
+    end
+
+  end
+end