We're obviously writing specs for arel. No need for a sub directory.

24 files changed, 2179 insertions, 0 deletions

diff --git a/spec/engines/sql/unit/engine_spec.rb b/spec/engines/sql/unit/engine_spec.rb
new file mode 100644
index 0000000000..f782f56938
--- /dev/null
+++ b/spec/engines/sql/unit/engine_spec.rb
@@ -0,0 +1,45 @@
+require 'spec_helper'
+
+module Arel
+  describe Sql::Engine do
+    before do
+      @users = Table.new(:users)
+      @users.delete
+    end
+
+    describe "CRUD" do
+      describe "#create" do
+        it "inserts into the relation" do
+          @users.insert @users[:name] => "Bryan"
+          @users.first[@users[:name]].should == "Bryan"
+        end
+      end
+
+      describe "#read" do
+        it "reads from the relation" do
+          @users.insert @users[:name] => "Bryan"
+
+          @users.each do |row|
+            row[@users[:name]].should == "Bryan"
+          end
+        end
+      end
+
+      describe "#update" do
+        it "updates the relation" do
+          @users.insert @users[:name] => "Nick"
+          @users.update @users[:name] => "Bryan"
+          @users.first[@users[:name]].should == "Bryan"
+        end
+      end
+
+      describe "#delete" do
+        it "deletes from the relation" do
+          @users.insert @users[:name] => "Bryan"
+          @users.delete
+          @users.first.should == nil
+        end
+      end
+    end
+  end
+end
diff --git a/spec/engines/sql/unit/predicates/binary_spec.rb b/spec/engines/sql/unit/predicates/binary_spec.rb
new file mode 100644
index 0000000000..72c8e44888
--- /dev/null
+++ b/spec/engines/sql/unit/predicates/binary_spec.rb
@@ -0,0 +1,140 @@
+require 'spec_helper'
+
+module Arel
+  module Predicates
+    describe Binary do
+      class ConcreteBinary < Binary
+        def predicate_sql
+          "<=>"
+        end
+      end
+
+      before do
+        @relation = Arel::Table.new(:users)
+        @attribute1 = @relation[:id]
+        @attribute2 = @relation[:name]
+      end
+
+      describe "with compound predicates" do
+        before do
+          @operand1 = ConcreteBinary.new(@attribute1, 1)
+          @operand2 = ConcreteBinary.new(@attribute2, "name")
+        end
+
+        describe Or do
+          describe "#to_sql" do
+            it "manufactures sql with an OR operation" do
+              sql = Or.new(@operand1, @operand2).to_sql
+
+              adapter_is :mysql do
+                sql.should be_like(%Q{(`users`.`id` <=> 1 OR `users`.`name` <=> 'name')})
+              end
+
+              adapter_is :postgresql do
+                sql.should be_like(%Q{("users"."id" <=> 1 OR "users"."name" <=> E'name')})
+              end
+
+              adapter_is :sqlite3 do
+                sql.should be_like(%Q{("users"."id" <=> 1 OR "users"."name" <=> 'name')})
+              end
+
+              adapter_is :oracle do
+                sql.should be_like(%Q{("USERS"."ID" <=> 1 OR "USERS"."NAME" <=> 'name')})
+              end
+            end
+          end
+        end
+
+        describe And do
+          describe "#to_sql" do
+            it "manufactures sql with an AND operation" do
+              sql = And.new(@operand1, @operand2).to_sql
+
+              adapter_is :mysql do
+                sql.should be_like(%Q{(`users`.`id` <=> 1 AND `users`.`name` <=> 'name')})
+              end
+
+              adapter_is :sqlite3 do
+                sql.should be_like(%Q{("users"."id" <=> 1 AND "users"."name" <=> 'name')})
+              end
+
+              adapter_is :postgresql do
+                sql.should be_like(%Q{("users"."id" <=> 1 AND "users"."name" <=> E'name')})
+              end
+
+              adapter_is :oracle do
+                sql.should be_like(%Q{("USERS"."ID" <=> 1 AND "USERS"."NAME" <=> 'name')})
+              end
+            end
+          end
+        end
+      end
+
+      describe '#to_sql' do
+        describe 'when relating two attributes' do
+          it 'manufactures sql with a binary operation' do
+            sql = ConcreteBinary.new(@attribute1, @attribute2).to_sql
+
+            adapter_is :mysql do
+              sql.should be_like(%Q{`users`.`id` <=> `users`.`name`})
+            end
+
+            adapter_is :oracle do
+              sql.should be_like(%Q{"USERS"."ID" <=> "USERS"."NAME"})
+            end
+
+            adapter_is_not :mysql, :oracle do
+              sql.should be_like(%Q{"users"."id" <=> "users"."name"})
+            end
+          end
+        end
+
+        describe 'when relating an attribute and a value' do
+          before do
+            @value = "1-asdf"
+          end
+
+          describe 'when relating to an integer attribute' do
+            it 'formats values as integers' do
+              sql = ConcreteBinary.new(@attribute1, @value).to_sql
+
+              adapter_is :mysql do
+                sql.should be_like(%Q{`users`.`id` <=> 1})
+              end
+
+              adapter_is :oracle do
+                sql.should be_like(%Q{"USERS"."ID" <=> 1})
+              end
+
+              adapter_is_not :mysql, :oracle do
+                sql.should be_like(%Q{"users"."id" <=> 1})
+              end
+            end
+          end
+
+          describe 'when relating to a string attribute' do
+            it 'formats values as strings' do
+              sql = ConcreteBinary.new(@attribute2, @value).to_sql
+
+              adapter_is :mysql do
+                sql.should be_like(%Q{`users`.`name` <=> '1-asdf'})
+              end
+
+              adapter_is :sqlite3 do
+                sql.should be_like(%Q{"users"."name" <=> '1-asdf'})
+              end
+
+              adapter_is :postgresql do
+                sql.should be_like(%Q{"users"."name" <=> E'1-asdf'})
+              end
+
+              adapter_is :oracle do
+                sql.should be_like(%Q{"USERS"."NAME" <=> '1-asdf'})
+              end
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/engines/sql/unit/predicates/equality_spec.rb b/spec/engines/sql/unit/predicates/equality_spec.rb
new file mode 100644
index 0000000000..bfd61185f2
--- /dev/null
+++ b/spec/engines/sql/unit/predicates/equality_spec.rb
@@ -0,0 +1,75 @@
+require 'spec_helper'
+
+module Arel
+  module Predicates
+    describe Equality do
+      before do
+        @relation1 = Arel::Table.new(:users)
+        @relation2 = Arel::Table.new(:photos)
+        @attribute1 = @relation1[:id]
+        @attribute2 = @relation2[:user_id]
+      end
+
+      describe '#to_sql' do
+        describe 'when relating to a non-nil value' do
+          it "manufactures an equality predicate" do
+            sql = Equality.new(@attribute1, @attribute2).to_sql
+
+            adapter_is :mysql do
+              sql.should be_like(%Q{`users`.`id` = `photos`.`user_id`})
+            end
+
+            adapter_is :oracle do
+              sql.should be_like(%Q{"USERS"."ID" = "PHOTOS"."USER_ID"})
+            end
+
+            adapter_is_not :mysql, :oracle do
+              sql.should be_like(%Q{"users"."id" = "photos"."user_id"})
+            end
+          end
+        end
+
+        describe 'when relation to a nil value' do
+          before do
+            @nil = nil
+          end
+
+          it "manufactures an is null predicate" do
+            sql = Equality.new(@attribute1, @nil).to_sql
+
+            adapter_is :mysql do
+              sql.should be_like(%Q{`users`.`id` IS NULL})
+            end
+
+            adapter_is :oracle do
+              sql.should be_like(%Q{"USERS"."ID" IS NULL})
+            end
+
+            adapter_is_not :mysql, :oracle do
+              sql.should be_like(%Q{"users"."id" IS NULL})
+            end
+          end
+        end
+
+        describe "when relating to a nil Value" do
+          it "manufactures an IS NULL predicate" do
+            value = nil.bind(@relation1)
+            sql = Equality.new(@attribute1, value).to_sql
+
+            adapter_is :mysql do
+              sql.should be_like(%Q{`users`.`id` IS NULL})
+            end
+
+            adapter_is :oracle do
+              sql.should be_like(%Q{"USERS"."ID" IS NULL})
+            end
+
+            adapter_is_not :mysql, :oracle do
+              sql.should be_like(%Q{"users"."id" IS NULL})
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/engines/sql/unit/predicates/in_spec.rb b/spec/engines/sql/unit/predicates/in_spec.rb
new file mode 100644
index 0000000000..5d9b2cdcaa
--- /dev/null
+++ b/spec/engines/sql/unit/predicates/in_spec.rb
@@ -0,0 +1,161 @@
+require 'spec_helper'
+
+module Arel
+  module Predicates
+    describe In do
+      before do
+        @relation = Arel::Table.new(:users)
+        @attribute = @relation[:id]
+      end
+
+      describe '#to_sql' do
+        describe 'when relating to an array' do
+          describe 'when the array\'s elements are the same type as the attribute' do
+            before do
+              @array = [1, 2, 3]
+            end
+
+            it 'manufactures sql with a comma separated list' do
+              sql = In.new(@attribute, @array).to_sql
+
+              adapter_is :mysql do
+                sql.should be_like(%Q{`users`.`id` IN (1, 2, 3)})
+              end
+
+              adapter_is :oracle do
+                sql.should be_like(%Q{"USERS"."ID" IN (1, 2, 3)})
+              end
+
+              adapter_is_not :mysql, :oracle do
+                sql.should be_like(%Q{"users"."id" IN (1, 2, 3)})
+              end
+            end
+          end
+
+          describe 'when the array\'s elements are not same type as the attribute' do
+            before do
+              @array = ['1-asdf', 2, 3]
+            end
+
+            it 'formats values in the array as the type of the attribute' do
+              sql = In.new(@attribute, @array).to_sql
+
+              adapter_is :mysql do
+                sql.should be_like(%Q{`users`.`id` IN (1, 2, 3)})
+              end
+
+              adapter_is :oracle do
+                sql.should be_like(%Q{"USERS"."ID" IN (1, 2, 3)})
+              end
+
+              adapter_is_not :mysql, :oracle do
+                sql.should be_like(%Q{"users"."id" IN (1, 2, 3)})
+              end
+            end
+          end
+
+          describe 'when the array is empty' do
+            before do
+              @array = []
+            end
+
+            it 'manufactures sql with a comma separated list' do
+              sql = In.new(@attribute, @array).to_sql
+
+              adapter_is :mysql do
+                sql.should be_like(%Q{`users`.`id` IN (NULL)})
+              end
+
+              adapter_is :oracle do
+                sql.should be_like(%Q{"USERS"."ID" IN (NULL)})
+              end
+
+              adapter_is_not :mysql, :oracle do
+                sql.should be_like(%Q{"users"."id" IN (NULL)})
+              end
+            end
+          end
+
+        end
+
+        describe 'when relating to a range' do
+          before do
+            @range = 1..2
+          end
+
+          it 'manufactures sql with a between' do
+            sql = In.new(@attribute, @range).to_sql
+
+            adapter_is :mysql do
+              sql.should be_like(%Q{`users`.`id` BETWEEN 1 AND 2})
+            end
+
+            adapter_is :oracle do
+              sql.should be_like(%Q{"USERS"."ID" BETWEEN 1 AND 2})
+            end
+
+            adapter_is_not :mysql, :oracle do
+              sql.should be_like(%Q{"users"."id" BETWEEN 1 AND 2})
+            end
+          end
+        end
+
+        describe 'when relating to a time range' do
+          before do
+            @relation = Arel::Table.new(:developers)
+            @attribute = @relation[:created_at]
+            @range = Time.mktime(2010, 01, 01)..Time.mktime(2010, 02, 01)
+          end
+
+          it 'manufactures sql with a between' do
+            sql = In.new(@attribute, @range).to_sql
+
+            adapter_is :mysql do
+              sql.should be_like(%Q{`developers`.`created_at` BETWEEN '2010-01-01 00:00:00' AND '2010-02-01 00:00:00'})
+            end
+
+            adapter_is :sqlite3 do
+              if RUBY_VERSION < '1.9'
+                sql.should be_like(%Q{"developers"."created_at" BETWEEN '2010-01-01 00:00:00.000000' AND '2010-02-01 00:00:00.000000'})
+              else
+                sql.should be_like(%Q{"developers"."created_at" BETWEEN '2010-01-01 00:00:00' AND '2010-02-01 00:00:00'})
+              end
+            end
+
+            adapter_is :postgresql do
+              sql.should be_like(%Q{"developers"."created_at" BETWEEN '2010-01-01 00:00:00.000000' AND '2010-02-01 00:00:00.000000'})
+            end
+
+            adapter_is :oracle do
+              sql.should be_like(%Q{"DEVELOPERS"."CREATED_AT" BETWEEN TO_TIMESTAMP('2010-01-01 00:00:00:000000','YYYY-MM-DD HH24:MI:SS:FF6') AND TO_TIMESTAMP('2010-02-01 00:00:00:000000','YYYY-MM-DD HH24:MI:SS:FF6')})
+            end
+          end
+        end
+
+        describe 'when relating to a relation' do
+          it 'manufactures sql with a subselect' do
+            sql = In.new(@attribute, @relation).to_sql
+
+            adapter_is :mysql do
+              sql.should be_like(%Q{
+                `users`.`id` IN (SELECT `users`.`id`, `users`.`name` FROM `users`)
+              })
+            end
+
+            adapter_is :oracle do
+              sql.should be_like(%Q{
+                "USERS"."ID" IN (SELECT "USERS"."ID", "USERS"."NAME" FROM "USERS")
+              })
+            end
+
+            adapter_is_not :mysql, :oracle do
+              sql.should be_like(%Q{
+                "users"."id" IN (SELECT "users"."id", "users"."name" FROM "users")
+              })
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/engines/sql/unit/predicates/predicates_spec.rb b/spec/engines/sql/unit/predicates/predicates_spec.rb
new file mode 100644
index 0000000000..e6130cf267
--- /dev/null
+++ b/spec/engines/sql/unit/predicates/predicates_spec.rb
@@ -0,0 +1,79 @@
+require 'spec_helper'
+
+module Arel
+  module Predicates
+    describe Predicate do
+      before do
+        @relation = Arel::Table.new(:users)
+        @attribute1 = @relation[:id]
+        @attribute2 = @relation[:name]
+        @operand1 = Arel::Predicates::Equality.new(@attribute1, 1)
+        @operand2 = Arel::Predicates::Equality.new(@attribute2, "name")
+      end
+
+      describe "when being combined with another predicate with AND logic" do
+        describe "#to_sql" do
+          it "manufactures sql with an AND operation" do
+            sql = @operand1.and(@operand2).to_sql
+
+            adapter_is :mysql do
+              sql.should be_like(%Q{
+                (`users`.`id` = 1 AND `users`.`name` = 'name')
+              })
+            end
+
+            adapter_is :sqlite3 do
+              sql.should be_like(%Q{
+                ("users"."id" = 1 AND "users"."name" = 'name')
+              })
+            end
+
+            adapter_is :postgresql do
+              sql.should be_like(%Q{
+                ("users"."id" = 1 AND "users"."name" = E'name')
+              })
+            end
+
+            adapter_is :oracle do
+              sql.should be_like(%Q{
+                ("USERS"."ID" = 1 AND "USERS"."NAME" = 'name')
+              })
+            end
+          end
+        end
+      end
+
+      describe "when being combined with another predicate with OR logic" do
+        describe "#to_sql" do
+          it "manufactures sql with an OR operation" do
+            sql = @operand1.or(@operand2).to_sql
+
+            adapter_is :mysql do
+              sql.should be_like(%Q{
+                (`users`.`id` = 1 OR `users`.`name` = 'name')
+              })
+            end
+
+            adapter_is :sqlite3 do
+              sql.should be_like(%Q{
+                ("users"."id" = 1 OR "users"."name" = 'name')
+              })
+            end
+
+            adapter_is :postgresql do
+              sql.should be_like(%Q{
+                ("users"."id" = 1 OR "users"."name" = E'name')
+              })
+            end
+
+            adapter_is :oracle do
+              sql.should be_like(%Q{
+                ("USERS"."ID" = 1 OR "USERS"."NAME" = 'name')
+              })
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/engines/sql/unit/primitives/attribute_spec.rb b/spec/engines/sql/unit/primitives/attribute_spec.rb
new file mode 100644
index 0000000000..c467d902ad
--- /dev/null
+++ b/spec/engines/sql/unit/primitives/attribute_spec.rb
@@ -0,0 +1,55 @@
+require 'spec_helper'
+
+module Arel
+  describe Attribute do
+    before do
+      @relation = Table.new(:users)
+      @attribute = @relation[:id]
+    end
+
+    describe '#column' do
+      it "returns the corresponding column in the relation" do
+        @attribute.column.should == @relation.column_for(@attribute)
+      end
+    end
+
+    describe '#to_sql' do
+      describe 'for a simple attribute' do
+        it "manufactures sql with an alias" do
+          sql = @attribute.to_sql
+
+          adapter_is :mysql do
+            sql.should be_like(%Q{`users`.`id`})
+          end
+
+          adapter_is :oracle do
+            sql.should be_like(%Q{"USERS"."ID"})
+          end
+
+          adapter_is_not :mysql, :oracle do
+            sql.should be_like(%Q{"users"."id"})
+          end
+        end
+      end
+
+      describe 'for an inexistent attribute' do
+        it "manufactures sql" do
+          sql = @relation[:does_not_exist].to_sql
+
+          adapter_is :mysql do
+            sql.should be_like(%Q{`users`.`does_not_exist`})
+          end
+
+          adapter_is :oracle do
+            sql.should be_like(%Q{"USERS"."DOEST_NOT_EXIST"})
+          end
+
+          adapter_is_not :mysql, :oracle do
+            sql.should be_like(%Q{"users"."does_not_exist"})
+          end
+        end
+      end
+
+    end
+  end
+end
diff --git a/spec/engines/sql/unit/primitives/expression_spec.rb b/spec/engines/sql/unit/primitives/expression_spec.rb
new file mode 100644
index 0000000000..3b6a7314a2
--- /dev/null
+++ b/spec/engines/sql/unit/primitives/expression_spec.rb
@@ -0,0 +1,28 @@
+require 'spec_helper'
+
+module Arel
+  describe Expression do
+    before do
+      @relation = Table.new(:users)
+      @attribute = @relation[:id]
+    end
+
+    describe '#to_sql' do
+      it "manufactures sql with the expression and alias" do
+        sql = Count.new(@attribute, :alias).to_sql
+
+        adapter_is :mysql do
+          sql.should be_like(%Q{COUNT(`users`.`id`) AS `alias`})
+        end
+
+        adapter_is :oracle do
+          sql.should be_like(%Q{COUNT("USERS"."ID") AS "ALIAS"})
+        end
+
+        adapter_is_not :mysql, :oracle do
+          sql.should be_like(%Q{COUNT("users"."id") AS "alias"})
+        end
+      end
+    end
+  end
+end
diff --git a/spec/engines/sql/unit/primitives/literal_spec.rb b/spec/engines/sql/unit/primitives/literal_spec.rb
new file mode 100644
index 0000000000..3bf60100f1
--- /dev/null
+++ b/spec/engines/sql/unit/primitives/literal_spec.rb
@@ -0,0 +1,43 @@
+require 'spec_helper'
+
+module Arel
+  describe SqlLiteral do
+    before do
+      @relation = Table.new(:users)
+    end
+
+    describe '#to_sql' do
+      it "manufactures sql with a literal SQL fragment" do
+        sql = @relation.project(Count.new(SqlLiteral.new("*"))).to_sql
+
+        adapter_is :mysql do
+          sql.should be_like(%Q{SELECT COUNT(*) AS count_id FROM `users`})
+        end
+
+        adapter_is :oracle do
+          sql.should be_like(%Q{SELECT COUNT(*) AS count_id FROM "USERS"})
+        end
+
+        adapter_is_not :mysql, :oracle do
+          sql.should be_like(%Q{SELECT COUNT(*) AS count_id FROM "users"})
+        end
+      end
+
+      it "manufactures expressions on literal SQL fragment" do
+        sql = @relation.project(SqlLiteral.new("2 * credit_limit").sum).to_sql
+
+        adapter_is :mysql do
+          sql.should be_like(%Q{SELECT SUM(2 * credit_limit) AS sum_id FROM `users`})
+        end
+
+        adapter_is :oracle do
+          sql.should be_like(%Q{SELECT SUM(2 * credit_limit) AS sum_id FROM "USERS"})
+        end
+
+        adapter_is_not :mysql, :oracle do
+          sql.should be_like(%Q{SELECT SUM(2 * credit_limit) AS sum_id FROM "users"})
+        end
+      end
+    end
+  end
+end
diff --git a/spec/engines/sql/unit/primitives/value_spec.rb b/spec/engines/sql/unit/primitives/value_spec.rb
new file mode 100644
index 0000000000..807090e31a
--- /dev/null
+++ b/spec/engines/sql/unit/primitives/value_spec.rb
@@ -0,0 +1,29 @@
+require 'spec_helper'
+
+module Arel
+  describe Value do
+    before do
+      @relation = Table.new(:users)
+    end
+
+    describe '#to_sql' do
+      it "appropriately quotes the value" do
+        Value.new(1, @relation).to_sql.should be_like('1')
+
+        adapter_is_not :postgresql do
+          Value.new('asdf', @relation).to_sql.should be_like("'asdf'")
+        end
+
+        adapter_is :postgresql do
+          Value.new('asdf', @relation).to_sql.should be_like("E'asdf'")
+        end
+      end
+    end
+
+    describe '#format' do
+      it "returns the sql of the provided object" do
+        Value.new(1, @relation).format(@relation[:id]).should == @relation[:id].to_sql
+      end
+    end
+  end
+end
diff --git a/spec/engines/sql/unit/relations/alias_spec.rb b/spec/engines/sql/unit/relations/alias_spec.rb
new file mode 100644
index 0000000000..a6fd7ab036
--- /dev/null
+++ b/spec/engines/sql/unit/relations/alias_spec.rb
@@ -0,0 +1,53 @@
+require 'spec_helper'
+
+module Arel
+  describe Alias do
+    before do
+      @relation = Table.new(:users)
+    end
+
+    describe '#to_sql' do
+      describe 'when there is no ambiguity' do
+        it 'does not alias table names anywhere a table name can appear' do
+          sql = @relation                 \
+            .where(@relation[:id].eq(1))  \
+            .order(@relation[:id])        \
+            .project(@relation[:id])      \
+            .group(@relation[:id])        \
+            .alias                        \
+          .to_sql
+
+          adapter_is :mysql do
+            sql.should be_like(%Q{
+              SELECT `users`.`id`
+              FROM `users`
+              WHERE `users`.`id` = 1
+              GROUP BY `users`.`id`
+              ORDER BY `users`.`id` ASC
+            })
+          end
+
+          adapter_is :oracle do
+            sql.should be_like(%Q{
+              SELECT "USERS"."ID"
+              FROM "USERS"
+              WHERE "USERS"."ID" = 1
+              GROUP BY "USERS"."ID"
+              ORDER BY "USERS"."ID" ASC
+            })
+          end
+
+          adapter_is_not :mysql, :oracle do
+            sql.should be_like(%Q{
+              SELECT "users"."id"
+              FROM "users"
+              WHERE "users"."id" = 1
+              GROUP BY "users"."id"
+              ORDER BY "users"."id" ASC
+            })
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/engines/sql/unit/relations/delete_spec.rb b/spec/engines/sql/unit/relations/delete_spec.rb
new file mode 100644
index 0000000000..302a13c688
--- /dev/null
+++ b/spec/engines/sql/unit/relations/delete_spec.rb
@@ -0,0 +1,83 @@
+require 'spec_helper'
+
+module Arel
+  describe Deletion do
+    before do
+      @relation = Table.new(:users)
+    end
+
+    describe '#to_sql' do
+      it 'manufactures sql deleting a table relation' do
+        sql = Deletion.new(@relation).to_sql
+
+        adapter_is :mysql do
+          sql.should be_like(%Q{DELETE FROM `users`})
+        end
+
+        adapter_is :oracle do
+          sql.should be_like(%Q{DELETE FROM "USERS"})
+        end
+
+        adapter_is_not :mysql, :oracle do
+          sql.should be_like(%Q{DELETE FROM "users"})
+        end
+      end
+
+      it 'manufactures sql deleting a where relation' do
+        sql = Deletion.new(@relation.where(@relation[:id].eq(1))).to_sql
+
+        adapter_is :mysql do
+          sql.should be_like(%Q{
+            DELETE
+            FROM `users`
+            WHERE `users`.`id` = 1
+          })
+        end
+
+        adapter_is :oracle do
+          sql.should be_like(%Q{
+            DELETE
+            FROM "USERS"
+            WHERE "USERS"."ID" = 1
+          })
+        end
+
+        adapter_is_not :mysql, :oracle do
+          sql.should be_like(%Q{
+            DELETE
+            FROM "users"
+            WHERE "users"."id" = 1
+          })
+        end
+      end
+
+      it "manufactures sql deleting a ranged relation" do
+        sql = Deletion.new(@relation.take(1)).to_sql
+
+        adapter_is :mysql do
+          sql.should be_like(%Q{
+            DELETE
+            FROM `users`
+            LIMIT 1
+          })
+        end
+
+        adapter_is :oracle do
+          sql.should be_like(%Q{
+            DELETE
+            FROM "USERS"
+            WHERE ROWNUM <= 1
+          })
+        end
+
+        adapter_is_not :mysql, :oracle do
+          sql.should be_like(%Q{
+            DELETE
+            FROM "users"
+            LIMIT 1
+          })
+        end
+      end
+    end
+  end
+end
diff --git a/spec/engines/sql/unit/relations/from_spec.rb b/spec/engines/sql/unit/relations/from_spec.rb
new file mode 100644
index 0000000000..0be3ac0f9a
--- /dev/null
+++ b/spec/engines/sql/unit/relations/from_spec.rb
@@ -0,0 +1,64 @@
+require 'spec_helper'
+
+module Arel
+  describe Table do
+    before do
+      @relation = Table.new(:users)
+    end
+
+    describe '#to_sql' do
+      it "manufactures a simple select query" do
+        sql = @relation.from("workers").to_sql
+
+        adapter_is :mysql do
+          sql.should be_like(%Q{
+            SELECT `users`.`id`, `users`.`name`
+            FROM workers
+          })
+        end
+
+        adapter_is :oracle do
+          sql.should be_like(%Q{
+            SELECT "USERS"."ID", "USERS"."NAME"
+            FROM workers
+          })
+        end
+
+        adapter_is_not :mysql, :oracle do
+          sql.should be_like(%Q{
+            SELECT "users"."id", "users"."name"
+            FROM workers
+          })
+        end
+      end
+    end
+
+    describe '#to_sql' do
+      it "overrides and use last from clause given " do
+        sql = @relation.from("workers").from("users").to_sql
+
+        adapter_is :mysql do
+          sql.should be_like(%Q{
+            SELECT `users`.`id`, `users`.`name`
+            FROM users
+          })
+        end
+
+        adapter_is :oracle do
+          sql.should be_like(%Q{
+            SELECT "USERS"."ID", "USERS"."NAME"
+            FROM users
+          })
+        end
+
+        adapter_is_not :mysql, :oracle do
+          sql.should be_like(%Q{
+            SELECT "users"."id", "users"."name"
+            FROM users
+          })
+        end
+      end
+    end
+
+  end
+end
diff --git a/spec/engines/sql/unit/relations/group_spec.rb b/spec/engines/sql/unit/relations/group_spec.rb
new file mode 100644
index 0000000000..72a9f4e99e
--- /dev/null
+++ b/spec/engines/sql/unit/relations/group_spec.rb
@@ -0,0 +1,72 @@
+require 'spec_helper'
+
+module Arel
+  describe Group do
+    before do
+      @relation = Table.new(:users)
+      @attribute = @relation[:id]
+    end
+
+    describe '#to_sql' do
+      describe 'when given a predicate' do
+        it "manufactures sql with where clause conditions" do
+          sql = Group.new(@relation, @attribute).to_sql
+
+          adapter_is :mysql do
+            sql.should be_like(%Q{
+              SELECT `users`.`id`, `users`.`name`
+              FROM `users`
+              GROUP BY `users`.`id`
+            })
+          end
+
+          adapter_is :oracle do
+            sql.should be_like(%Q{
+              SELECT "USERS"."ID", "USERS"."NAME"
+              FROM "USERS"
+              GROUP BY "USERS"."ID"
+            })
+          end
+
+          adapter_is_not :mysql, :oracle do
+            sql.should be_like(%Q{
+              SELECT "users"."id", "users"."name"
+              FROM "users"
+              GROUP BY "users"."id"
+            })
+          end
+        end
+      end
+
+      describe 'when given a string' do
+        it "passes the string through to the where clause" do
+          sql = Group.new(@relation, 'asdf').to_sql
+
+          adapter_is :mysql do
+            sql.should be_like(%Q{
+              SELECT `users`.`id`, `users`.`name`
+              FROM `users`
+              GROUP BY asdf
+            })
+          end
+
+          adapter_is :oracle do
+            sql.should be_like(%Q{
+              SELECT "USERS"."ID", "USERS"."NAME"
+              FROM "USERS"
+              GROUP BY asdf
+            })
+          end
+
+          adapter_is_not :mysql, :oracle do
+            sql.should be_like(%Q{
+              SELECT "users"."id", "users"."name"
+              FROM "users"
+              GROUP BY asdf
+            })
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/engines/sql/unit/relations/having_spec.rb b/spec/engines/sql/unit/relations/having_spec.rb
new file mode 100644
index 0000000000..fe6f3cc520
--- /dev/null
+++ b/spec/engines/sql/unit/relations/having_spec.rb
@@ -0,0 +1,45 @@
+require 'spec_helper'
+
+module Arel
+  describe Having do
+    before do
+      @relation = Table.new(:developers)
+    end
+
+    describe '#to_sql' do
+      describe 'when given a predicate' do
+        it "manufactures sql with where clause conditions" do
+          sql = @relation.group(@relation[:department]).having("MIN(salary) > 1000").to_sql
+
+          adapter_is :mysql do
+            sql.should be_like(%Q{
+              SELECT `developers`.`id`, `developers`.`name`, `developers`.`salary`, `developers`.`department`, `developers`.`created_at`
+              FROM `developers`
+              GROUP BY `developers`.`department`
+              HAVING MIN(salary) > 1000
+            })
+          end
+
+          adapter_is :oracle do
+            sql.should be_like(%Q{
+              SELECT "DEVELOPERS"."ID", "DEVELOPERS"."NAME", "DEVELOPERS"."SALARY", "DEVELOPERS"."DEPARTMENT", "DEVELOPERS"."CREATED_AT"
+              FROM "DEVELOPERS"
+              GROUP BY "DEVELOPERS"."DEPARTMENT"
+              HAVING MIN(salary) > 1000
+            })
+          end
+
+          adapter_is_not :mysql, :oracle do
+            sql.should be_like(%Q{
+              SELECT "developers"."id", "developers"."name", "developers"."salary", "developers"."department", "developers"."created_at"
+              FROM "developers"
+              GROUP BY "developers"."department"
+              HAVING MIN(salary) > 1000
+            })
+          end
+        end
+      end
+    end
+  end
+end
+
diff --git a/spec/engines/sql/unit/relations/insert_spec.rb b/spec/engines/sql/unit/relations/insert_spec.rb
new file mode 100644
index 0000000000..4b412093e4
--- /dev/null
+++ b/spec/engines/sql/unit/relations/insert_spec.rb
@@ -0,0 +1,143 @@
+require 'spec_helper'
+
+module Arel
+  describe Insert do
+    before do
+      @relation = Table.new(:users)
+    end
+
+    describe '#to_sql' do
+      it 'manufactures sql inserting data when given multiple rows' do
+        pending 'it should insert multiple rows' do
+          @insertion = Insert.new(@relation, [@relation[:name] => "nick", @relation[:name] => "bryan"])
+
+          @insertion.to_sql.should be_like("
+            INSERT
+            INTO `users`
+            (`name`) VALUES ('nick'), ('bryan')
+          ")
+        end
+      end
+
+      it 'manufactures sql inserting data when given multiple values' do
+        @insertion = Insert.new(@relation, @relation[:id] => "1", @relation[:name] => "nick")
+
+        adapter_is :mysql do
+          @insertion.to_sql.should be_like(%Q{
+            INSERT
+            INTO `users`
+            (`id`, `name`) VALUES (1, 'nick')
+          })
+        end
+
+        adapter_is :sqlite3 do
+          @insertion.to_sql.should be_like(%Q{
+            INSERT
+            INTO "users"
+            ("id", "name") VALUES (1, 'nick')
+          })
+        end
+
+        adapter_is :postgresql do
+          @insertion.to_sql.should be_like(%Q{
+            INSERT
+            INTO "users"
+            ("id", "name") VALUES (1, E'nick')
+            RETURNING "id"
+          })
+        end
+
+        adapter_is :oracle do
+          @insertion.to_sql.should be_like(%Q{
+            INSERT
+            INTO "USERS"
+            ("ID", "NAME") VALUES (1, 'nick')
+          })
+        end
+      end
+
+      describe 'when given values whose types correspond to the types of the attributes' do
+        before do
+          @insertion = Insert.new(@relation, @relation[:name] => "nick")
+        end
+
+        it 'manufactures sql inserting data' do
+          adapter_is :mysql do
+            @insertion.to_sql.should be_like(%Q{
+              INSERT
+              INTO `users`
+              (`name`) VALUES ('nick')
+            })
+          end
+
+          adapter_is :sqlite3 do
+            @insertion.to_sql.should be_like(%Q{
+              INSERT
+              INTO "users"
+              ("name") VALUES ('nick')
+            })
+          end
+
+          adapter_is :postgresql do
+            @insertion.to_sql.should be_like(%Q{
+              INSERT
+              INTO "users"
+              ("name") VALUES (E'nick')
+              RETURNING "id"
+            })
+          end
+
+          adapter_is :oracle do
+            @insertion.to_sql.should be_like(%Q{
+              INSERT
+              INTO "USERS"
+              ("NAME") VALUES ('nick')
+            })
+          end
+        end
+      end
+
+      describe 'when given values whose types differ from from the types of the attributes' do
+        before do
+          @insertion = Insert.new(@relation, @relation[:id] => '1-asdf')
+        end
+
+        it 'manufactures sql inserting data' do
+          adapter_is :mysql do
+            @insertion.to_sql.should be_like(%Q{
+              INSERT
+              INTO `users`
+              (`id`) VALUES (1)
+            })
+          end
+
+          adapter_is :sqlite3 do
+            @insertion.to_sql.should be_like(%Q{
+              INSERT
+              INTO "users"
+              ("id") VALUES (1)
+            })
+          end
+
+          adapter_is :postgresql do
+            @insertion.to_sql.should be_like(%Q{
+              INSERT
+              INTO "users"
+              ("id") VALUES (1)
+              RETURNING "id"
+            })
+          end
+
+          adapter_is :oracle do
+            @insertion.to_sql.should be_like(%Q{
+              INSERT
+              INTO "USERS"
+              ("ID") VALUES (1)
+            })
+          end
+
+        end
+      end
+    end
+  end
+end
diff --git a/spec/engines/sql/unit/relations/join_spec.rb b/spec/engines/sql/unit/relations/join_spec.rb
new file mode 100644
index 0000000000..cbbcb18244
--- /dev/null
+++ b/spec/engines/sql/unit/relations/join_spec.rb
@@ -0,0 +1,180 @@
+require 'spec_helper'
+
+module Arel
+  describe Join do
+    before do
+      @relation1 = Table.new(:users)
+      @relation2 = Table.new(:photos)
+      @predicate1 = @relation1[:id].eq(@relation2[:user_id])
+
+      @relation3 = Table.new(:users, :as => :super_users)
+      @relation4 = Table.new(:photos, :as => :super_photos)
+
+      @predicate2 = @relation3[:id].eq(@relation2[:user_id])
+      @predicate3 = @relation3[:id].eq(@relation4[:user_id])
+    end
+
+    describe '#to_sql' do
+
+      describe 'when joining with another relation' do
+        it 'manufactures sql joining the two tables on the predicate' do
+          sql = InnerJoin.new(@relation1, @relation2, @predicate1).to_sql
+
+          adapter_is :mysql do
+            sql.should be_like(%Q{
+              SELECT `users`.`id`, `users`.`name`, `photos`.`id`, `photos`.`user_id`, `photos`.`camera_id`
+              FROM `users`
+                INNER JOIN `photos` ON `users`.`id` = `photos`.`user_id`
+            })
+          end
+
+          adapter_is :oracle do
+            sql.should be_like(%Q{
+              SELECT "USERS"."ID", "USERS"."NAME", "PHOTOS"."ID", "PHOTOS"."USER_ID", "PHOTOS"."CAMERA_ID"
+              FROM "USERS"
+                INNER JOIN "PHOTOS" ON "USERS"."ID" = "PHOTOS"."USER_ID"
+            })
+          end
+
+          adapter_is_not :mysql, :oracle do
+            sql.should be_like(%Q{
+              SELECT "users"."id", "users"."name", "photos"."id", "photos"."user_id", "photos"."camera_id"
+              FROM "users"
+                INNER JOIN "photos" ON "users"."id" = "photos"."user_id"
+            })
+          end
+        end
+
+        describe 'when joining with another relation with an aliased table' do
+          it 'manufactures sql joining the two tables on the predicate respecting table aliasing' do
+            sql = InnerJoin.new(@relation3, @relation2, @predicate2).to_sql
+
+            adapter_is :mysql do
+              sql.should be_like(%Q{
+                SELECT `super_users`.`id`, `super_users`.`name`, `photos`.`id`, `photos`.`user_id`, `photos`.`camera_id`
+                FROM `users` `super_users`
+                  INNER JOIN `photos` ON `super_users`.`id` = `photos`.`user_id`
+              })
+            end
+
+            adapter_is :oracle do
+              sql.should be_like(%Q{
+                SELECT "SUPER_USERS"."ID", "SUPER_USERS"."NAME", "PHOTOS"."ID", "PHOTOS"."USER_ID", "PHOTOS"."CAMERA_ID"
+                FROM "USERS" "SUPER_USERS"
+                  INNER JOIN "PHOTOS" ON "SUPER_USERS"."ID" = "PHOTOS"."USER_ID"
+              })
+            end
+
+            adapter_is_not :mysql, :oracle do
+              sql.should be_like(%Q{
+                SELECT "super_users"."id", "super_users"."name", "photos"."id", "photos"."user_id", "photos"."camera_id"
+                FROM "users" "super_users"
+                  INNER JOIN "photos" ON "super_users"."id" = "photos"."user_id"
+              })
+            end
+          end
+        end
+
+        describe 'when joining with two relations with aliased tables' do
+          it 'manufactures sql joining the two tables on the predicate respecting table aliasing' do
+            sql = InnerJoin.new(@relation3, @relation4, @predicate3).to_sql
+
+            adapter_is :mysql do
+              sql.should be_like(%Q{
+                SELECT `super_users`.`id`, `super_users`.`name`, `super_photos`.`id`, `super_photos`.`user_id`, `super_photos`.`camera_id`
+                FROM `users` `super_users`
+                  INNER JOIN `photos` `super_photos` ON `super_users`.`id` = `super_photos`.`user_id`
+              })
+            end
+
+            adapter_is :oracle do
+              sql.should be_like(%Q{
+                SELECT "SUPER_USERS"."ID", "SUPER_USERS"."NAME", "SUPER_PHOTOS"."ID", "SUPER_PHOTOS"."USER_ID", "SUPER_PHOTOS"."CAMERA_ID"
+                FROM "USERS" "SUPER_USERS"
+                  INNER JOIN "PHOTOS" "SUPER_PHOTOS" ON "SUPER_USERS"."ID" = "SUPER_PHOTOS"."USER_ID"
+              })
+            end
+
+            adapter_is_not :mysql, :oracle do
+              sql.should be_like(%Q{
+                SELECT "super_users"."id", "super_users"."name", "super_photos"."id", "super_photos"."user_id", "super_photos"."camera_id"
+                FROM "users" "super_users"
+                  INNER JOIN "photos" "super_photos" ON "super_users"."id" = "super_photos"."user_id"
+              })
+            end
+          end
+        end
+
+      end
+
+      describe 'when joining with a string' do
+        it "passes the string through to the where clause" do
+          sql = StringJoin.new(@relation1, "INNER JOIN asdf ON fdsa").to_sql
+
+          adapter_is :mysql do
+            sql.should be_like(%Q{
+              SELECT `users`.`id`, `users`.`name`
+              FROM `users`
+                INNER JOIN asdf ON fdsa
+            })
+          end
+
+          adapter_is :oracle do
+            sql.should be_like(%Q{
+              SELECT "USERS"."ID", "USERS"."NAME"
+              FROM "USERS"
+                INNER JOIN asdf ON fdsa
+            })
+          end
+
+          adapter_is_not :mysql, :oracle do
+            sql.should be_like(%Q{
+              SELECT "users"."id", "users"."name"
+              FROM "users"
+                INNER JOIN asdf ON fdsa
+            })
+          end
+        end
+
+        it "passes the string when there are multiple string joins" do
+          relation = StringJoin.new(@relation1, "INNER JOIN asdf ON fdsa")
+          relation = StringJoin.new(relation, "INNER JOIN lifo ON fifo")
+          sql = StringJoin.new(relation, "INNER JOIN hatful ON hallow").to_sql
+
+          adapter_is :mysql do
+            sql.should be_like(%Q{
+              SELECT `users`.`id`, `users`.`name`
+              FROM `users`
+                INNER JOIN asdf ON fdsa
+                INNER JOIN lifo ON fifo
+                INNER JOIN hatful ON hallow
+            })
+          end
+
+          adapter_is :oracle do
+            sql.should be_like(%Q{
+              SELECT "USERS"."ID", "USERS"."NAME"
+              FROM "USERS"
+                INNER JOIN asdf ON fdsa
+                INNER JOIN lifo ON fifo
+                INNER JOIN hatful ON hallow
+            })
+          end
+
+          adapter_is_not :mysql, :oracle do
+            sql.should be_like(%Q{
+              SELECT "users"."id", "users"."name"
+              FROM "users"
+                INNER JOIN asdf ON fdsa
+                INNER JOIN lifo ON fifo
+                INNER JOIN hatful ON hallow
+            })
+          end
+        end
+
+    end
+
+
+    end
+  end
+end
diff --git a/spec/engines/sql/unit/relations/lock_spec.rb b/spec/engines/sql/unit/relations/lock_spec.rb
new file mode 100644
index 0000000000..72a8a2e457
--- /dev/null
+++ b/spec/engines/sql/unit/relations/lock_spec.rb
@@ -0,0 +1,86 @@
+require 'spec_helper'
+
+module Arel
+  describe Lock do
+    before do
+      @relation = Table.new(:users)
+    end
+
+    describe '#to_sql' do
+      it "manufactures a simple select query lock" do
+        sql = @relation.lock.to_sql
+
+        adapter_is :mysql do
+          sql.should be_like(%Q{
+            SELECT `users`.`id`, `users`.`name`
+            FROM `users` FOR UPDATE
+          })
+        end
+
+        adapter_is :postgresql do
+          sql.should be_like(%Q{
+            SELECT "users"."id", "users"."name"
+            FROM "users" FOR UPDATE
+          })
+        end
+
+        adapter_is :sqlite3 do
+          sql.should be_like(%Q{
+            SELECT "users"."id", "users"."name"
+            FROM "users"
+          })
+        end
+
+        adapter_is :oracle do
+          sql.should be_like(%Q{
+            SELECT "USERS"."ID", "USERS"."NAME"
+            FROM "USERS" FOR UPDATE
+          })
+
+          sql_with_order_by = @relation.order(@relation[:id]).take(1).lock.to_sql
+          sql_with_order_by.should be_like(%Q{
+            SELECT "USERS"."ID", "USERS"."NAME"
+            FROM "USERS"
+            WHERE "ID" IN (select * from
+                          (SELECT "ID" FROM "USERS" ORDER BY "USERS"."ID" ASC)
+                          where rownum <= 1)
+            FOR UPDATE
+          })
+
+        end
+      end
+
+      it "manufactures a select query locking with a given lock" do
+        sql = @relation.lock("LOCK IN SHARE MODE").to_sql
+
+        adapter_is :mysql do
+          sql.should be_like(%Q{
+            SELECT `users`.`id`, `users`.`name`
+            FROM `users` LOCK IN SHARE MODE
+          })
+        end
+
+        adapter_is :postgresql do
+          sql.should be_like(%Q{
+            SELECT "users"."id", "users"."name"
+            FROM "users" LOCK IN SHARE MODE
+          })
+        end
+
+        adapter_is :sqlite3 do
+          sql.should be_like(%Q{
+            SELECT "users"."id", "users"."name"
+            FROM "users"
+          })
+        end
+
+        adapter_is :oracle do
+          sql.should be_like(%Q{
+            SELECT "USERS"."ID", "USERS"."NAME"
+            FROM "USERS" LOCK IN SHARE MODE
+          })
+        end
+      end
+    end
+  end
+end
diff --git a/spec/engines/sql/unit/relations/order_spec.rb b/spec/engines/sql/unit/relations/order_spec.rb
new file mode 100644
index 0000000000..3c9d9ef598
--- /dev/null
+++ b/spec/engines/sql/unit/relations/order_spec.rb
@@ -0,0 +1,161 @@
+require 'spec_helper'
+
+module Arel
+  describe Order do
+    before do
+      @relation = Table.new(:users)
+      @attribute = @relation[:id]
+    end
+
+    describe '#to_sql' do
+      describe "when given an attribute" do
+        it "manufactures sql with an order clause populated by the attribute" do
+          sql = Order.new(@relation, @attribute).to_sql
+
+          adapter_is :mysql do
+            sql.should be_like(%Q{
+              SELECT `users`.`id`, `users`.`name`
+              FROM `users`
+              ORDER BY `users`.`id` ASC
+            })
+          end
+
+          adapter_is :oracle do
+            sql.should be_like(%Q{
+              SELECT "USERS"."ID", "USERS"."NAME"
+              FROM "USERS"
+              ORDER BY "USERS"."ID" ASC
+            })
+
+            distinct_attributes = ActiveRecord::Base.connection.distinct('"USERS"."NAME"', '"USERS"."ID"')
+            @relation.project(distinct_attributes).order(@relation[:id]).to_sql.should be_like(%Q{
+              SELECT DISTINCT "USERS"."NAME",
+              FIRST_VALUE("USERS"."ID") OVER (PARTITION BY "USERS"."NAME" ORDER BY "USERS"."ID") AS alias_0__
+              FROM "USERS"
+              ORDER BY alias_0__
+            })
+
+            distinct_attributes = ActiveRecord::Base.connection.distinct('"USERS"."NAME"', '"USERS"."ID" DESC')
+            @relation.project(distinct_attributes).order('"USERS"."ID" DESC').to_sql.should be_like(%Q{
+              SELECT DISTINCT "USERS"."NAME",
+              FIRST_VALUE("USERS"."ID") OVER (PARTITION BY "USERS"."NAME" ORDER BY "USERS"."ID" DESC) AS alias_0__
+              FROM "USERS"
+              ORDER BY alias_0__ DESC
+            })
+          end
+
+          adapter_is_not :mysql, :oracle do
+            sql.should be_like(%Q{
+              SELECT "users"."id", "users"."name"
+              FROM "users"
+              ORDER BY "users"."id" ASC
+            })
+          end
+        end
+      end
+
+      describe "when given multiple attributes" do
+        before do
+          @another_attribute = @relation[:name]
+        end
+
+        it "manufactures sql with an order clause populated by comma-separated attributes" do
+          sql = Order.new(@relation, @attribute, @another_attribute).to_sql
+
+          adapter_is :mysql do
+            sql.should be_like(%Q{
+              SELECT `users`.`id`, `users`.`name`
+              FROM `users`
+              ORDER BY `users`.`id` ASC, `users`.`name` ASC
+            })
+          end
+
+          adapter_is :oracle do
+            sql.should be_like(%Q{
+              SELECT "USERS"."ID", "USERS"."NAME"
+              FROM "USERS"
+              ORDER BY "USERS"."ID" ASC, "USERS"."NAME" ASC
+            })
+          end
+
+          adapter_is_not :mysql, :oracle do
+            sql.should be_like(%Q{
+              SELECT "users"."id", "users"."name"
+              FROM "users"
+              ORDER BY "users"."id" ASC, "users"."name" ASC
+            })
+          end
+        end
+      end
+
+      describe "when given a string" do
+        before do
+          @string = "asdf"
+        end
+
+        it "passes the string through to the order clause" do
+          sql = Order.new(@relation, @string).to_sql
+
+          adapter_is :mysql do
+            sql.should be_like(%Q{
+              SELECT `users`.`id`, `users`.`name`
+              FROM `users`
+              ORDER BY asdf
+            })
+          end
+
+          adapter_is :oracle do
+            sql.should be_like(%Q{
+              SELECT "USERS"."ID", "USERS"."NAME"
+              FROM "USERS"
+              ORDER BY asdf
+            })
+          end
+
+          adapter_is_not :mysql, :oracle do
+            sql.should be_like(%Q{
+              SELECT "users"."id", "users"."name"
+              FROM "users"
+              ORDER BY asdf
+            })
+          end
+        end
+      end
+
+      describe "when ordering an ordered relation" do
+        before do
+          @ordered_relation = Order.new(@relation, @attribute)
+          @another_attribute = @relation[:name]
+        end
+
+        it "manufactures sql with the order clause of the last ordering preceding the first ordering" do
+          sql = Order.new(@ordered_relation, @another_attribute).to_sql
+
+          adapter_is :mysql do
+            sql.should be_like(%Q{
+              SELECT `users`.`id`, `users`.`name`
+              FROM `users`
+              ORDER BY `users`.`name` ASC, `users`.`id` ASC
+            })
+          end
+
+          adapter_is :oracle do
+            sql.should be_like(%Q{
+              SELECT "USERS"."ID", "USERS"."NAME"
+              FROM "USERS"
+              ORDER BY "USERS"."NAME" ASC, "USERS"."ID" ASC
+            })
+          end
+
+          adapter_is_not :mysql, :oracle do
+            sql.should be_like(%Q{
+              SELECT "users"."id", "users"."name"
+              FROM "users"
+              ORDER BY "users"."name" ASC, "users"."id" ASC
+            })
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/engines/sql/unit/relations/project_spec.rb b/spec/engines/sql/unit/relations/project_spec.rb
new file mode 100644
index 0000000000..e73c7775a1
--- /dev/null
+++ b/spec/engines/sql/unit/relations/project_spec.rb
@@ -0,0 +1,143 @@
+require 'spec_helper'
+
+module Arel
+  describe Project do
+    before do
+      @relation = Table.new(:users)
+      @attribute = @relation[:id]
+    end
+
+    describe '#to_sql' do
+      describe 'when given an attribute' do
+        it "manufactures sql with a limited select clause" do
+          sql = Project.new(@relation, @attribute).to_sql
+
+          adapter_is :mysql do
+            sql.should be_like(%Q{
+              SELECT `users`.`id`
+              FROM `users`
+            })
+          end
+
+          adapter_is :oracle do
+            sql.should be_like(%Q{
+              SELECT "USERS"."ID"
+              FROM "USERS"
+            })
+          end
+
+          adapter_is_not :mysql, :oracle do
+            sql.should be_like(%Q{
+              SELECT "users"."id"
+              FROM "users"
+            })
+          end
+        end
+      end
+
+      describe 'when given a relation' do
+        before do
+          @scalar_relation = Project.new(@relation, @relation[:name])
+        end
+
+        it "manufactures sql with scalar selects" do
+          sql = Project.new(@relation, @scalar_relation).to_sql
+
+          adapter_is :mysql do
+            sql.should be_like(%Q{
+              SELECT (SELECT `users`.`name` FROM `users`) AS `users` FROM `users`
+            })
+          end
+
+          adapter_is :oracle do
+            sql.should be_like(%Q{
+              SELECT (SELECT "USERS"."NAME" FROM "USERS") AS "USERS" FROM "USERS"
+            })
+          end
+
+          adapter_is_not :mysql, :oracle do
+            sql.should be_like(%Q{
+              SELECT (SELECT "users"."name" FROM "users") AS "users" FROM "users"
+            })
+          end
+        end
+      end
+
+      describe 'when given a string' do
+        it "passes the string through to the select clause" do
+          sql = Project.new(@relation, 'asdf').to_sql
+
+          adapter_is :mysql do
+            sql.should be_like(%Q{
+              SELECT asdf FROM `users`
+            })
+          end
+
+          adapter_is :oracle do
+            sql.should be_like(%Q{
+              SELECT asdf FROM "USERS"
+            })
+          end
+
+          adapter_is_not :mysql, :oracle do
+            sql.should be_like(%Q{
+              SELECT asdf FROM "users"
+            })
+          end
+        end
+      end
+
+      describe 'when given an expression' do
+        it 'manufactures sql with expressions' do
+          sql = @relation.project(@attribute.count).to_sql
+
+          adapter_is :mysql do
+            sql.should be_like(%Q{
+              SELECT COUNT(`users`.`id`) AS count_id
+              FROM `users`
+            })
+          end
+
+          adapter_is :oracle do
+            sql.should be_like(%Q{
+              SELECT COUNT("USERS"."ID") AS count_id
+              FROM "USERS"
+            })
+          end
+
+          adapter_is_not :mysql, :oracle do
+            sql.should be_like(%Q{
+              SELECT COUNT("users"."id") AS count_id
+              FROM "users"
+            })
+          end
+        end
+
+        it 'manufactures sql with distinct expressions' do
+          sql = @relation.project(@attribute.count(true)).to_sql
+
+          adapter_is :mysql do
+            sql.should be_like(%Q{
+              SELECT COUNT(DISTINCT `users`.`id`) AS count_id
+              FROM `users`
+            })
+          end
+
+          adapter_is :oracle do
+            sql.should be_like(%Q{
+              SELECT COUNT(DISTINCT "USERS"."ID") AS count_id
+              FROM "USERS"
+            })
+          end
+
+          adapter_is_not :mysql, :oracle do
+            sql.should be_like(%Q{
+              SELECT COUNT(DISTINCT "users"."id") AS count_id
+              FROM "users"
+            })
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/engines/sql/unit/relations/skip_spec.rb b/spec/engines/sql/unit/relations/skip_spec.rb
new file mode 100644
index 0000000000..41b80d12d8
--- /dev/null
+++ b/spec/engines/sql/unit/relations/skip_spec.rb
@@ -0,0 +1,41 @@
+require 'spec_helper'
+
+module Arel
+  describe Skip do
+    before do
+      @relation = Table.new(:users)
+      @skipped = 4
+    end
+
+    describe '#to_sql' do
+      it "manufactures sql with limit and offset" do
+        sql = Skip.new(@relation, @skipped).to_sql
+
+        adapter_is :mysql do
+          sql.should be_like(%Q{
+            SELECT `users`.`id`, `users`.`name`
+            FROM `users`
+            OFFSET 4
+          })
+        end
+
+        adapter_is :oracle do
+          sql.should be_like(%Q{
+            select * from (select raw_sql_.*, rownum raw_rnum_ from
+            (SELECT "USERS"."ID", "USERS"."NAME"
+            FROM "USERS") raw_sql_)
+            where raw_rnum_ > 4
+          })
+        end
+
+        adapter_is_not :mysql, :oracle do
+          sql.should be_like(%Q{
+            SELECT "users"."id", "users"."name"
+            FROM "users"
+            OFFSET 4
+          })
+        end
+      end
+    end
+  end
+end
diff --git a/spec/engines/sql/unit/relations/table_spec.rb b/spec/engines/sql/unit/relations/table_spec.rb
new file mode 100644
index 0000000000..6afd9964a4
--- /dev/null
+++ b/spec/engines/sql/unit/relations/table_spec.rb
@@ -0,0 +1,129 @@
+require 'spec_helper'
+
+module Arel
+  describe Table do
+    before do
+      @relation = Table.new(:users)
+    end
+
+    describe '#to_sql' do
+      it "manufactures a simple select query" do
+        sql = @relation.to_sql
+
+        adapter_is :mysql do
+          sql.should be_like(%Q{
+            SELECT `users`.`id`, `users`.`name`
+            FROM `users`
+          })
+        end
+
+        adapter_is :oracle do
+          sql.should be_like(%Q{
+            SELECT "USERS"."ID", "USERS"."NAME"
+            FROM "USERS"
+          })
+        end
+
+        adapter_is_not :mysql, :oracle do
+          sql.should be_like(%Q{
+            SELECT "users"."id", "users"."name"
+            FROM "users"
+          })
+        end
+      end
+    end
+
+    describe '#as' do
+      it "manufactures a simple select query using aliases" do
+        sql = @relation.as(:super_users).to_sql
+
+        adapter_is :mysql do
+          sql.should be_like(%Q{
+            SELECT `super_users`.`id`, `super_users`.`name`
+            FROM `users` `super_users`
+          })
+        end
+
+        adapter_is :oracle do
+          sql.should be_like(%Q{
+            SELECT "SUPER_USERS"."ID", "SUPER_USERS"."NAME"
+            FROM "USERS" "SUPER_USERS"
+          })
+        end
+
+        adapter_is_not :mysql, :oracle do
+          sql.should be_like(%Q{
+            SELECT "super_users"."id", "super_users"."name"
+            FROM "users" "super_users"
+          })
+        end
+      end
+
+      it "does not apply alias if it's same as the table name" do
+        sql = @relation.as(:users).to_sql
+
+        adapter_is :mysql do
+          sql.should be_like(%Q{
+            SELECT `users`.`id`, `users`.`name`
+            FROM `users`
+          })
+        end
+
+        adapter_is :oracle do
+          sql.should be_like(%Q{
+            SELECT "USERS"."ID", "USERS"."NAME"
+            FROM "USERS"
+          })
+        end
+
+        adapter_is_not :mysql, :oracle do
+          sql.should be_like(%Q{
+            SELECT "users"."id", "users"."name"
+            FROM "users"
+          })
+        end
+      end
+
+    end
+
+    describe '#column_for' do
+      it "returns the column corresponding to the attribute" do
+        @relation.column_for(@relation[:id]).should == @relation.columns.detect { |c| c.name == 'id' }
+      end
+    end
+
+    describe '#attributes' do
+      it 'manufactures attributes corresponding to columns in the table' do
+        @relation.attributes.should == [
+          Attribute.new(@relation, :id),
+          Attribute.new(@relation, :name)
+        ]
+      end
+
+      describe '#reset' do
+        it "reloads columns from the database" do
+          lambda { @relation.engine.stub!(:columns => []) }.should_not change { @relation.attributes }
+          lambda { @relation.reset                        }.should     change { @relation.attributes }
+        end
+      end
+    end
+
+    describe 'hashing' do
+      it "implements hash equality" do
+        Table.new(:users).should     hash_the_same_as(Table.new(:users))
+        Table.new(:users).should_not hash_the_same_as(Table.new(:photos))
+      end
+    end
+
+    describe '#engine' do
+      it "defaults to global engine" do
+        Table.engine = engine = Sql::Engine.new
+        Table.new(:users).engine.should == engine
+      end
+
+      it "can be specified" do
+        Table.new(:users, engine = Sql::Engine.new).engine.should == engine
+      end
+    end
+  end
+end
diff --git a/spec/engines/sql/unit/relations/take_spec.rb b/spec/engines/sql/unit/relations/take_spec.rb
new file mode 100644
index 0000000000..9f2967a0bd
--- /dev/null
+++ b/spec/engines/sql/unit/relations/take_spec.rb
@@ -0,0 +1,49 @@
+require 'spec_helper'
+
+module Arel
+  describe Take do
+    before do
+      @relation = Table.new(:users)
+      @taken = 4
+    end
+
+    describe '#to_sql' do
+      it "manufactures sql with limit and offset" do
+        sql = Take.new(@relation, @taken).to_sql
+
+        adapter_is :mysql do
+          sql.should be_like(%Q{
+            SELECT `users`.`id`, `users`.`name`
+            FROM `users`
+            LIMIT 4
+          })
+        end
+
+        adapter_is :oracle do
+          sql.should be_like(%Q{
+            SELECT "USERS"."ID", "USERS"."NAME"
+            FROM "USERS"
+            WHERE ROWNUM <= 4
+          })
+
+          sql_with_order_by = Take.new(@relation.order(@relation[:id]), @taken).to_sql
+          sql_with_order_by.should be_like(%Q{
+            select * from
+            (SELECT "USERS"."ID", "USERS"."NAME"
+            FROM "USERS"
+            ORDER BY "USERS"."ID" ASC)
+            where rownum <= 4
+          })
+        end
+
+        adapter_is_not :mysql, :oracle do
+          sql.should be_like(%Q{
+            SELECT "users"."id", "users"."name"
+            FROM "users"
+            LIMIT 4
+          })
+        end
+      end
+    end
+  end
+end
diff --git a/spec/engines/sql/unit/relations/update_spec.rb b/spec/engines/sql/unit/relations/update_spec.rb
new file mode 100644
index 0000000000..cc2ad9913b
--- /dev/null
+++ b/spec/engines/sql/unit/relations/update_spec.rb
@@ -0,0 +1,203 @@
+require 'spec_helper'
+
+class User
+  def self.primary_key
+    "id"
+  end
+end
+
+module Arel
+  describe Update do
+    before do
+      @relation = Table.new(:users)
+    end
+
+    describe '#to_sql' do
+      it "manufactures sql updating attributes when given multiple attributes" do
+        sql = Update.new(@relation, @relation[:id] => 1, @relation[:name] => "nick").to_sql
+
+        adapter_is :mysql do
+          sql.should be_like(%Q{
+            UPDATE `users`
+            SET `id` = 1, `name` = 'nick'
+          })
+        end
+
+        adapter_is :sqlite3 do
+          sql.should be_like(%Q{
+            UPDATE "users"
+            SET "id" = 1, "name" = 'nick'
+          })
+        end
+
+        adapter_is :postgresql do
+          sql.should be_like(%Q{
+            UPDATE "users"
+            SET "id" = 1, "name" = E'nick'
+          })
+        end
+
+        adapter_is :oracle do
+          sql.should be_like(%Q{
+            UPDATE "USERS"
+            SET "ID" = 1, "NAME" = 'nick'
+          })
+        end
+      end
+
+      it "manufactures sql updating attributes when given a ranged relation" do
+        sql = Update.new(@relation.take(1), @relation[:name] => "nick").to_sql
+
+        adapter_is :mysql do
+          sql.should be_like(%Q{
+            UPDATE `users`
+            SET `name` = 'nick'
+            LIMIT 1
+          })
+        end
+
+        adapter_is :sqlite3 do
+          sql.should be_like(%Q{
+            UPDATE "users" SET
+            "name" = 'nick'
+            WHERE "id" IN (SELECT "id" FROM "users"  LIMIT 1)
+          })
+        end
+
+        adapter_is :postgresql do
+          sql.should be_like(%Q{
+            UPDATE "users" SET
+            "name" = E'nick'
+            WHERE "id" IN (SELECT "id" FROM "users"  LIMIT 1)
+          })
+        end
+
+        adapter_is :oracle do
+          sql.should be_like(%Q{
+            UPDATE "USERS" SET
+            "NAME" = 'nick'
+            WHERE "ID" IN (SELECT "ID" FROM "USERS" WHERE ROWNUM <= 1)
+          })
+
+          sql_with_order_by = Update.new(@relation.order(@relation[:id]).take(1), @relation[:name] => "nick").to_sql
+          sql_with_order_by.should be_like(%Q{
+            UPDATE "USERS" SET
+            "NAME" = 'nick'
+            WHERE "ID" IN (select * from
+                          (SELECT "ID" FROM "USERS" ORDER BY "USERS"."ID" ASC)
+                          where rownum <= 1)
+          })
+        end
+      end
+
+      describe 'when given values whose types correspond to the types of the attributes' do
+        before do
+          @update = Update.new(@relation, @relation[:name] => "nick")
+        end
+
+        it 'manufactures sql updating attributes' do
+          adapter_is :mysql do
+            @update.to_sql.should be_like(%Q{
+              UPDATE `users`
+              SET `name` = 'nick'
+            })
+          end
+
+          adapter_is :sqlite3 do
+            @update.to_sql.should be_like(%Q{
+              UPDATE "users"
+              SET "name" = 'nick'
+            })
+          end
+
+          adapter_is :postgresql do
+            @update.to_sql.should be_like(%Q{
+              UPDATE "users"
+              SET "name" = E'nick'
+            })
+          end
+
+          adapter_is :oracle do
+            @update.to_sql.should be_like(%Q{
+              UPDATE "USERS"
+              SET "NAME" = 'nick'
+            })
+          end
+        end
+      end
+
+      describe 'when given values whose types differ from from the types of the attributes' do
+        before do
+          @update = Update.new(@relation, @relation[:id] => '1-asdf')
+        end
+
+        it 'manufactures sql updating attributes' do
+          adapter_is :mysql do
+            @update.to_sql.should be_like(%Q{
+              UPDATE `users`
+              SET `id` = 1
+            })
+          end
+
+          adapter_is :oracle do
+            @update.to_sql.should be_like(%Q{
+              UPDATE "USERS"
+              SET "ID" = 1
+            })
+          end
+
+          adapter_is_not :mysql, :oracle do
+            @update.to_sql.should be_like(%Q{
+              UPDATE "users"
+              SET "id" = 1
+            })
+          end
+        end
+      end
+
+      describe 'when the relation is a where' do
+        before do
+          @update = Update.new(
+            @relation.where(@relation[:id].eq(1)),
+            @relation[:name] => "nick"
+          )
+        end
+
+        it 'manufactures sql updating a where relation' do
+          adapter_is :mysql do
+            @update.to_sql.should be_like(%Q{
+              UPDATE `users`
+              SET `name` = 'nick'
+              WHERE `users`.`id` = 1
+            })
+          end
+
+          adapter_is :sqlite3 do
+            @update.to_sql.should be_like(%Q{
+              UPDATE "users"
+              SET "name" = 'nick'
+              WHERE "users"."id" = 1
+            })
+          end
+
+          adapter_is :postgresql do
+            @update.to_sql.should be_like(%Q{
+              UPDATE "users"
+              SET "name" = E'nick'
+              WHERE "users"."id" = 1
+            })
+          end
+
+          adapter_is :oracle do
+            @update.to_sql.should be_like(%Q{
+              UPDATE "USERS"
+              SET "NAME" = 'nick'
+              WHERE "USERS"."ID" = 1
+            })
+          end
+        end
+      end
+    end
+
+  end
+end
diff --git a/spec/engines/sql/unit/relations/where_spec.rb b/spec/engines/sql/unit/relations/where_spec.rb
new file mode 100644
index 0000000000..5f559efad3
--- /dev/null
+++ b/spec/engines/sql/unit/relations/where_spec.rb
@@ -0,0 +1,72 @@
+require 'spec_helper'
+
+module Arel
+  describe Where do
+    before do
+      @relation = Table.new(:users)
+      @predicate = @relation[:id].eq(1)
+    end
+
+    describe '#to_sql' do
+      describe 'when given a predicate' do
+        it "manufactures sql with where clause conditions" do
+          sql = Where.new(@relation, @predicate).to_sql
+
+          adapter_is :mysql do
+            sql.should be_like(%Q{
+              SELECT `users`.`id`, `users`.`name`
+              FROM `users`
+              WHERE `users`.`id` = 1
+            })
+          end
+
+          adapter_is :oracle do
+            sql.should be_like(%Q{
+              SELECT "USERS"."ID", "USERS"."NAME"
+              FROM "USERS"
+              WHERE "USERS"."ID" = 1
+            })
+          end
+
+          adapter_is_not :mysql, :oracle do
+            sql.should be_like(%Q{
+              SELECT "users"."id", "users"."name"
+              FROM "users"
+              WHERE "users"."id" = 1
+            })
+          end
+        end
+      end
+
+      describe 'when given a string' do
+        it "passes the string through to the where clause" do
+          sql = Where.new(@relation, 'asdf').to_sql
+
+          adapter_is :mysql do
+            sql.should be_like(%Q{
+              SELECT `users`.`id`, `users`.`name`
+              FROM `users`
+              WHERE asdf
+            })
+          end
+
+          adapter_is :oracle do
+            sql.should be_like(%Q{
+              SELECT "USERS"."ID", "USERS"."NAME"
+              FROM "USERS"
+              WHERE asdf
+            })
+          end
+
+          adapter_is_not :mysql, :oracle do
+            sql.should be_like(%Q{
+              SELECT "users"."id", "users"."name"
+              FROM "users"
+              WHERE asdf
+            })
+          end
+        end
+      end
+    end
+  end
+end