From 448a342d5ff4de1844c8cde4730b61af36b9dc7c Mon Sep 17 00:00:00 2001
From: Loic Nageleisen <loic.nageleisen@gmail.com>
Date: Fri, 3 Mar 2017 14:53:28 +0100
Subject: [PATCH] arbitrary functions

---
 lib/rebel/sql.rb | 9 +++++++++
 test/test_raw.rb | 4 ++++
 2 files changed, 13 insertions(+)

diff --git a/lib/rebel/sql.rb b/lib/rebel/sql.rb
index 252dd5a..d36b537 100644
--- a/lib/rebel/sql.rb
+++ b/lib/rebel/sql.rb
@@ -218,6 +218,11 @@ module Rebel::SQL
 
     ## Functions
 
+    def function(name, *args)
+      raw("#{name}(#{names_or_values(*args)})")
+    end
+    alias fn function
+
     def count(*n)
       raw("COUNT(#{names(*n)})")
     end
@@ -282,6 +287,10 @@ module Rebel::SQL
       item.is_a?(Symbol) ? name(item) : value(item)
     end
 
+    def names_or_values(*items)
+      list(items.map { |v| name_or_value(v) })
+    end
+
     def equal(l, r)
       "#{name_or_value(l)} = #{name_or_value(r)}"
     end
diff --git a/test/test_raw.rb b/test/test_raw.rb
index 9d5b707..cf84d20 100644
--- a/test/test_raw.rb
+++ b/test/test_raw.rb
@@ -68,4 +68,8 @@ class TestRaw < Minitest::Test
   def test_join
     assert_str_equal(Rebel::SQL.join(:foo), 'JOIN "foo"')
   end
+
+  def test_function
+    assert_str_equal(Rebel::SQL.function('COALESCE', :foo, 0), 'COALESCE("foo", 0)')
+  end
 end