Merge remote branch 'miloops/master' into miloops

Conflicts:
	spec/connections/mysql_connection.rb
	spec/connections/postgresql_connection.rb
	spec/connections/sqlite3_connection.rb

5 files changed, 72 insertions, 13 deletions

diff --git a/lib/arel/engines/sql/formatters.rb b/lib/arel/engines/sql/formatters.rb
index ae80feb18e..626803a887 100644
--- a/lib/arel/engines/sql/formatters.rb
+++ b/lib/arel/engines/sql/formatters.rb
@@ -13,7 +13,6 @@ module Arel
 
     class SelectClause < Formatter
       def attribute(attribute)
-        # FIXME this should check that the column exists
         "#{quote_table_name(name_for(attribute.original_relation))}.#{quote_column_name(attribute.name)}" +
         (attribute.alias ? " AS #{quote(attribute.alias.to_s)}" : "")
       end
@@ -92,8 +91,12 @@ module Arel
       end
 
       def table(table)
-        quote_table_name(table.name) +
-        (table.name != name_for(table) ? " AS " + quote_table_name(name_for(table)) : '')
+        if table.name =~ /\s/
+          table.name
+        else
+          quote_table_name(table.name) +
+            (table.name != name_for(table) ? " AS " + quote_table_name(name_for(table)) : '')
+        end
       end
     end
 
diff --git a/lib/arel/engines/sql/primitives.rb b/lib/arel/engines/sql/primitives.rb
index 16e1abdf59..6cce46a441 100644
--- a/lib/arel/engines/sql/primitives.rb
+++ b/lib/arel/engines/sql/primitives.rb
@@ -7,6 +7,8 @@ module Arel
     def to_sql(formatter = nil)
       self
     end
+
+    include Attribute::Expressions
   end
 
   class Attribute
diff --git a/lib/arel/engines/sql/relations/operations/join.rb b/lib/arel/engines/sql/relations/operations/join.rb
index 7c5e13510a..a3aaaa163b 100644
--- a/lib/arel/engines/sql/relations/operations/join.rb
+++ b/lib/arel/engines/sql/relations/operations/join.rb
@@ -26,8 +26,8 @@ module Arel
   end
 
   class StringJoin < Join
-    def joins(_, __ = nil)
-      relation2
+    def joins(environment, formatter = Sql::TableReference.new(environment))
+       [relation1.joins(environment), relation2].compact.join(" ")
     end
   end
 end
diff --git a/lib/arel/engines/sql/relations/relation.rb b/lib/arel/engines/sql/relations/relation.rb
index 4cfb83a601..ed7f19ddbd 100644
--- a/lib/arel/engines/sql/relations/relation.rb
+++ b/lib/arel/engines/sql/relations/relation.rb
@@ -5,6 +5,26 @@ module Arel
     end
 
     def select_sql
+      if engine.adapter_name == "PostgreSQL" && !orders.blank? && using_distinct_on?
+        # PostgreSQL does not allow arbitrary ordering when using DISTINCT ON, so we work around this
+        # by wrapping the +sql+ string as a sub-select and ordering in that query.
+        order = order_clauses.join(', ').split(',').map { |s| s.strip }.reject(&:blank?)
+        order = order.zip((0...order.size).to_a).map { |s,i| "id_list.alias_#{i} #{'DESC' if s =~ /\bdesc$/i}" }.join(', ')
+
+        query = build_query \
+          "SELECT     #{select_clauses.to_s}",
+          "FROM       #{table_sql(Sql::TableReference.new(self))}",
+          (joins(self)                                   unless joins(self).blank? ),
+          ("WHERE     #{where_clauses.join("\n\tAND ")}" unless wheres.blank?      ),
+          ("GROUP BY  #{group_clauses.join(', ')}"       unless groupings.blank?   )
+
+        build_query \
+          "SELECT * FROM (#{query}) AS id_list",
+          "ORDER BY #{order}",
+          ("LIMIT     #{taken}"                          unless taken.blank?       ),
+          ("OFFSET    #{skipped}"                        unless skipped.blank?     )
+
+      else
       build_query \
         "SELECT     #{select_clauses.join(', ')}",
         "FROM       #{table_sql(Sql::TableReference.new(self))}",
@@ -14,6 +34,7 @@ module Arel
         ("ORDER BY  #{order_clauses.join(', ')}"       unless orders.blank?      ),
         ("LIMIT     #{taken}"                          unless taken.blank?       ),
         ("OFFSET    #{skipped}"                        unless skipped.blank?     )
+      end
     end
 
     def inclusion_predicate_sql
@@ -46,5 +67,8 @@ module Arel
       orders.collect { |o| o.to_sql(Sql::OrderClause.new(self)) }
     end
 
+    def using_distinct_on?
+      select_clauses.any? { |x| x =~ /DISTINCT ON/ }
+    end
   end
 end
diff --git a/lib/arel/engines/sql/relations/writes.rb b/lib/arel/engines/sql/relations/writes.rb
index f1a9bfd2ac..d648a54d91 100644
--- a/lib/arel/engines/sql/relations/writes.rb
+++ b/lib/arel/engines/sql/relations/writes.rb
@@ -11,11 +11,17 @@ module Arel
 
   class Insert < Compound
     def to_sql(formatter = nil)
+      insertion_attributes_values_sql = if record.is_a?(Value)
+        record.value
+      else
+        build_query "(#{record.keys.collect { |key| engine.quote_column_name(key.name) }.join(', ')})",
+          "VALUES (#{record.collect { |key, value| key.format(value) }.join(', ')})"
+      end
+
       build_query \
         "INSERT",
         "INTO #{table_sql}",
-        "(#{record.keys.collect { |key| engine.quote_column_name(key.name) }.join(', ')})",
-        "VALUES (#{record.collect { |key, value| key.format(value) }.join(', ')})"
+        insertion_attributes_values_sql
     end
   end
 
@@ -24,16 +30,40 @@ module Arel
       build_query \
         "UPDATE #{table_sql} SET",
         assignment_sql,
-        ("WHERE #{wheres.collect(&:to_sql).join('\n\tAND ')}"  unless wheres.blank? ),
-        ("LIMIT #{taken}"                                      unless taken.blank?  )
+        build_update_conditions_sql
     end
 
   protected
-
     def assignment_sql
-      assignments.collect do |attribute, value|
-        "#{engine.quote_column_name(attribute.name)} = #{attribute.format(value)}"
-      end.join(",\n")
+      if assignments.respond_to?(:collect)
+        assignments.collect do |attribute, value|
+          "#{engine.quote_column_name(attribute.name)} = #{attribute.format(value)}"
+        end.join(",\n")
+      else
+        assignments.value
+      end
+    end
+
+    def build_update_conditions_sql
+      conditions = ""
+      conditions << " WHERE #{wheres.collect(&:to_sql).join('\n\tAND ')}" unless wheres.blank?
+      conditions << " ORDER BY #{order_clauses.join(', ')}" unless orders.blank?
+
+      unless taken.blank?
+        conditions << " LIMIT #{taken}"
+
+        if engine.adapter_name != "MySQL"
+          begin
+            quote_primary_key = engine.quote_column_name(table.name.classify.constantize.primary_key)
+          rescue NameError
+            quote_primary_key = engine.quote_column_name("id")
+          end
+
+          conditions =  "WHERE #{quote_primary_key} IN (SELECT #{quote_primary_key} FROM #{engine.connection.quote_table_name table.name} #{conditions})"
+        end
+      end
+
+      conditions
     end
   end
 end