Added Arel::Nodes::NamedFunction for representing generic SQL functions

History.txt

@@ -5,6 +5,7 @@
   * AST is now Enumerable
   * AND nodes are now n-ary nodes
   * SQL Literals may be used as Attribute names
+  * Added Arel::Nodes::NamedFunction for representing generic SQL functions
 
 * Deprecations
 

Manifest.txt

@@ -28,6 +28,7 @@ lib/arel/nodes/inner_join.rb
 lib/arel/nodes/insert_statement.rb
 lib/arel/nodes/join_source.rb
 lib/arel/nodes/lock.rb
+lib/arel/nodes/named_function.rb
 lib/arel/nodes/node.rb
 lib/arel/nodes/ordering.rb
 lib/arel/nodes/outer_join.rb
@@ -52,6 +53,7 @@ lib/arel/visitors.rb
 lib/arel/visitors/depth_first.rb
 lib/arel/visitors/dot.rb
 lib/arel/visitors/join_sql.rb
+lib/arel/visitors/mssql.rb
 lib/arel/visitors/mysql.rb
 lib/arel/visitors/oracle.rb
 lib/arel/visitors/order_clauses.rb
@@ -67,6 +69,7 @@ test/nodes/test_count.rb
 test/nodes/test_delete_statement.rb
 test/nodes/test_equality.rb
 test/nodes/test_insert_statement.rb
+test/nodes/test_named_function.rb
 test/nodes/test_node.rb
 test/nodes/test_not.rb
 test/nodes/test_or.rb
@@ -88,6 +91,7 @@ test/test_update_manager.rb
 test/visitors/test_depth_first.rb
 test/visitors/test_dot.rb
 test/visitors/test_join_sql.rb
+test/visitors/test_mssql.rb
 test/visitors/test_mysql.rb
 test/visitors/test_oracle.rb
 test/visitors/test_postgres.rb

lib/arel/nodes.rb

@@ -28,6 +28,7 @@
 require 'arel/nodes/function'
 require 'arel/nodes/count'
 require 'arel/nodes/values'
+require 'arel/nodes/named_function'
 
 # joins
 require 'arel/nodes/inner_join'

lib/arel/nodes/count.rb

 module Arel
   module Nodes
     class Count < Arel::Nodes::Function
-
-      attr_accessor :distinct
-
       def initialize expr, distinct = false, aliaz = nil
         super(expr, aliaz)
         @distinct = distinct

lib/arel/nodes/function.rb

@@ -2,11 +2,12 @@ module Arel
   module Nodes
     class Function < Arel::Nodes::Node
       include Arel::Expression
-      attr_accessor :expressions, :alias
+      attr_accessor :expressions, :alias, :distinct
 
       def initialize expr, aliaz = nil
         @expressions = expr
         @alias       = aliaz
+        @distinct    = false
       end
 
       def as aliaz

lib/arel/nodes/named_function.rb

+module Arel
+  module Nodes
+    class NamedFunction < Arel::Nodes::Function
+      attr_accessor :name
+
+      def initialize name, expr, aliaz = nil
+        super(expr, aliaz)
+        @name = name
+      end
+    end
+  end
+end

lib/arel/visitors/depth_first.rb

@@ -28,6 +28,7 @@ def unary o
       def function o
         visit o.expressions
         visit o.alias
+        visit o.distinct
       end
       alias :visit_Arel_Nodes_Avg    :function
       alias :visit_Arel_Nodes_Exists :function
@@ -35,6 +36,13 @@ def function o
       alias :visit_Arel_Nodes_Min    :function
       alias :visit_Arel_Nodes_Sum    :function
 
+      def visit_Arel_Nodes_NamedFunction o
+        visit o.name
+        visit o.expressions
+        visit o.distinct
+        visit o.alias
+      end
+
       def visit_Arel_Nodes_Count o
         visit o.expressions
         visit o.alias

lib/arel/visitors/dot.rb

@@ -38,13 +38,6 @@ def visit_Arel_Nodes_TableAlias o
         visit_edge o, "relation"
       end
 
-      def visit_Arel_Nodes_Sum o
-        visit_edge o, "expressions"
-        visit_edge o, "alias"
-      end
-      alias :visit_Arel_Nodes_Max :visit_Arel_Nodes_Sum
-      alias :visit_Arel_Nodes_Avg :visit_Arel_Nodes_Sum
-
       def visit_Arel_Nodes_Count o
         visit_edge o, "expressions"
         visit_edge o, "distinct"
@@ -82,6 +75,24 @@ def unary o
       alias :visit_Arel_Nodes_Top               :unary
       alias :visit_Arel_Nodes_UnqualifiedColumn :unary
 
+      def function o
+        visit_edge o, "expressions"
+        visit_edge o, "distinct"
+        visit_edge o, "alias"
+      end
+      alias :visit_Arel_Nodes_Exists :function
+      alias :visit_Arel_Nodes_Min    :function
+      alias :visit_Arel_Nodes_Max    :function
+      alias :visit_Arel_Nodes_Avg    :function
+      alias :visit_Arel_Nodes_Sum    :function
+
+      def visit_Arel_Nodes_NamedFunction o
+        visit_edge o, "name"
+        visit_edge o, "expressions"
+        visit_edge o, "distinct"
+        visit_edge o, "alias"
+      end
+
       def visit_Arel_Nodes_InsertStatement o
         visit_edge o, "relation"
         visit_edge o, "columns"

lib/arel/visitors/to_sql.rb

@@ -183,6 +183,12 @@ def visit_Arel_Nodes_Group o
         visit o.expr
       end
 
+      def visit_Arel_Nodes_NamedFunction o
+        "#{o.name}(#{o.distinct ? 'DISTINCT ' : ''}#{o.expressions.map { |x|
+          visit x
+        }.join(', ')})#{o.alias ? " AS #{visit o.alias}" : ''}"
+      end
+
       def visit_Arel_Nodes_Count o
         "COUNT(#{o.distinct ? 'DISTINCT ' : ''}#{o.expressions.map { |x|
           visit x

test/nodes/test_named_function.rb

+require 'helper'
+
+module Arel
+  module Nodes
+    class TestNamedFunction < MiniTest::Unit::TestCase
+      def test_construct
+        function = NamedFunction.new 'omg', 'zomg'
+        assert_equal 'omg', function.name
+        assert_equal 'zomg', function.expressions
+      end
+    end
+  end
+end

test/nodes/test_node.rb

@@ -11,6 +11,7 @@ def test_all_nodes_are_nodes
         Nodes.const_get(k)
       }.grep(Class).each do |klass|
         next if Nodes::SqlLiteral == klass
+        next if klass.name =~ /^Arel::Nodes::Test/
         assert klass.ancestors.include?(Nodes::Node), klass.name
       end
     end

test/visitors/test_depth_first.rb

@@ -52,10 +52,16 @@ def test_raises_with_object
         define_method("test_#{klass.name.gsub('::', '_')}") do
           func = klass.new(:a, :b)
           @visitor.accept func
-          assert_equal [:a, :b, func], @collector.calls
+          assert_equal [:a, :b, false, func], @collector.calls
         end
       end
 
+      def test_named_function
+        func = Arel::Nodes::NamedFunction.new(:a, :b, :c)
+        @visitor.accept func
+        assert_equal [:a, :b, false, :c, func], @collector.calls
+      end
+
       def test_lock
         lock = Nodes::Lock.new
         @visitor.accept lock

test/visitors/test_dot.rb

@@ -7,6 +7,25 @@ def setup
         @visitor = Visitors::Dot.new
       end
 
+      # functions
+      [
+        Nodes::Sum,
+        Nodes::Exists,
+        Nodes::Max,
+        Nodes::Min,
+        Nodes::Avg,
+      ].each do |klass|
+        define_method("test_#{klass.name.gsub('::', '_')}") do
+          op = klass.new(:a, :z)
+          @visitor.accept op
+        end
+      end
+
+      def test_named_function
+        func = Nodes::NamedFunction.new 'omg', 'omg'
+        @visitor.accept func
+      end
+
       # unary ops
       [
         Arel::Nodes::Not,

test/visitors/test_to_sql.rb

@@ -15,6 +15,16 @@ module Visitors
         sql.must_be_like '"users".*'
       end
 
+      it 'should visit named functions' do
+        function = Nodes::NamedFunction.new('omg', [Arel.star])
+        assert_equal 'omg(*)', @visitor.accept(function)
+      end
+
+      it 'works with lists' do
+        function = Nodes::NamedFunction.new('omg', [Arel.star, Arel.star])
+        assert_equal 'omg(*, *)', @visitor.accept(function)
+      end
+
       describe 'equality' do
         it 'should handle false' do
           sql = @visitor.accept Nodes::Equality.new(false, false)