Add #extract, which produces ANSI SQL function EXTRACT(<field> from <expr>).

1 files changed, 23 insertions, 0 deletions

diff --git a/lib/arel/nodes/extract.rb b/lib/arel/nodes/extract.rb
new file mode 100644
index 0000000000..1c9ee78816
--- /dev/null
+++ b/lib/arel/nodes/extract.rb
@@ -0,0 +1,23 @@
+module Arel
+  module Nodes
+
+    class Extract < Arel::Nodes::Unary
+      include Arel::Expression
+      include Arel::Predications
+
+      attr_accessor :field
+      attr_accessor :alias
+
+      def initialize expr, field, aliaz = nil
+        super(expr)
+        @field = field
+        @alias = aliaz && SqlLiteral.new(aliaz)
+      end
+
+      def as aliaz
+        self.alias = SqlLiteral.new(aliaz)
+        self
+      end
+    end
+  end
+end