diff --git a/lib/sql_dust.ex b/lib/sql_dust.ex
index 6563df4..f042ae3 100644
--- a/lib/sql_dust.ex
+++ b/lib/sql_dust.ex
@@ -42,7 +42,6 @@ defmodule SqlDust do
 
   defp derive_select(options) do
     list = split_arguments(options[:select])
-
     {select, options} = list
       |> prepend_path_aliases(options)
 
diff --git a/lib/sql_dust/utils/join_utils.ex b/lib/sql_dust/utils/join_utils.ex
index e9d93a1..89f5aea 100644
--- a/lib/sql_dust/utils/join_utils.ex
+++ b/lib/sql_dust/utils/join_utils.ex
@@ -104,7 +104,6 @@ defmodule SqlDust.JoinUtils do
       |> Enum.map(fn(join) ->
         {left_key, _} = prepend_path_alias(join.left_key, options)
         {right_key, _} = prepend_path_alias(join.right_key, options)
-
         additional_conditions = join[:join_on]
                                   |> List.wrap
                                   |> Enum.concat(additional_join_conditions(join.path, options))
diff --git a/lib/sql_dust/utils/path_utils.ex b/lib/sql_dust/utils/path_utils.ex
index 06e8af7..263e3b3 100644
--- a/lib/sql_dust/utils/path_utils.ex
+++ b/lib/sql_dust/utils/path_utils.ex
@@ -37,7 +37,6 @@ defmodule SqlDust.PathUtils do
       |> Enum.concat(Enum.map(aliases, fn(sql_alias) ->
         [~r/([^\.\w])#{sql_alias}([^\.\w])/, quote_alias(sql_alias, options)]
       end))
-
     options = Map.put(options, :aliases, aliases)
 
     sql = numerize_patterns(sql, excluded)
@@ -63,7 +62,7 @@ defmodule SqlDust.PathUtils do
       |> Enum.concat(scan_reserved_words(sql))
       |> List.flatten
       |> Enum.uniq
-
+      
     {excluded, aliases}
   end
 
diff --git a/lib/sql_dust/utils/scan_utils.ex b/lib/sql_dust/utils/scan_utils.ex
index e7b0e36..216692c 100644
--- a/lib/sql_dust/utils/scan_utils.ex
+++ b/lib/sql_dust/utils/scan_utils.ex
@@ -10,17 +10,14 @@ defmodule SqlDust.ScanUtils do
 
   def split_arguments(sql) do
     excluded = scan_quoted(sql)
-
     {sql, excluded} = numerize_patterns(sql, excluded)
       |> numerize_parenthesized(excluded)
-
     {list, _} = sql
       |> String.split(~r/\s*,\s*/)
       |> Enum.reduce({[], excluded}, fn(sql, {list, excluded}) ->
         sql = interpolate_parenthesized(sql, excluded)
         {List.insert_at(list, -1, sql), excluded}
       end)
-
     list
   end
 
@@ -33,7 +30,6 @@ defmodule SqlDust.ScanUtils do
       patterns = patterns
         |> Enum.concat(parenthesized)
         |> List.flatten
-        |> Enum.uniq
       numerize_patterns(sql, patterns)
         |> numerize_parenthesized(patterns)
     end
@@ -59,6 +55,10 @@ defmodule SqlDust.ScanUtils do
       end)
   end
 
+  def scan_existing_alias(sql) do
+    Regex.scan(~r/ AS \".+\"/i, sql)
+  end
+
   def scan_variables(sql) do
     Regex.scan(~r/<<[\w\.]+>>/, sql)
   end
@@ -72,11 +72,11 @@ defmodule SqlDust.ScanUtils do
   end
 
   def scan_aliases(sql) do
-    Regex.scan(~r/ AS .+$/i, sql)
+    Regex.scan(~r/ AS .+?(?=\)|$)/i, sql)
   end
 
   def scan_reserved_words(sql) do
-    Regex.scan(~r/\b(distinct|and|or|is|like|rlike|regexp|in|between|not|null|sounds|soundex|asc|desc|true|false)\b/i, sql)
+    Regex.scan(~r/\b(distinct|and|as|or|is|like|rlike|point|bigint|bigserial|bit|bit|varying|boolean|bytea|character|character|varying|date|double|precision|integer|numeric|real|serial|smallint|text|time|with|timezone|timestamp|with|timezone|xml|regexp|in|interval|between|not|null|sounds|soundex|asc|desc|true|false)\b/i, sql)
   end
 
   def numerize_patterns(sql, patterns) do