Merge commit 'brynary/master'

Conflicts:

	lib/arel.rb
	lib/arel/session.rb

21 files changed, 1356 insertions, 0 deletions

diff --git a/spec/arel/engines/sql/unit/engine_spec.rb b/spec/arel/engines/sql/unit/engine_spec.rb
new file mode 100644
index 0000000000..c607abcfa1
--- /dev/null
+++ b/spec/arel/engines/sql/unit/engine_spec.rb
@@ -0,0 +1,45 @@
+require File.join(File.dirname(__FILE__), '..', '..', '..', '..', '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/arel/engines/sql/unit/predicates/binary_spec.rb b/spec/arel/engines/sql/unit/predicates/binary_spec.rb
new file mode 100644
index 0000000000..b1400e2588
--- /dev/null
+++ b/spec/arel/engines/sql/unit/predicates/binary_spec.rb
@@ -0,0 +1,117 @@
+require File.join(File.dirname(__FILE__), '..', '..', '..', '..', '..', 'spec_helper')
+
+module Arel
+  describe Binary do
+    before do
+      @relation = Table.new(:users)
+      @attribute1 = @relation[:id]
+      @attribute2 = @relation[:name]
+      class ConcreteBinary < Binary
+        def predicate_sql
+          "<=>"
+        end
+      end
+    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
+          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
+          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_not :mysql 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_not :mysql 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
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/arel/engines/sql/unit/predicates/equality_spec.rb b/spec/arel/engines/sql/unit/predicates/equality_spec.rb
new file mode 100644
index 0000000000..688a6a20be
--- /dev/null
+++ b/spec/arel/engines/sql/unit/predicates/equality_spec.rb
@@ -0,0 +1,46 @@
+require File.join(File.dirname(__FILE__), '..', '..', '..', '..', '..', 'spec_helper')
+
+module Arel
+  describe Equality do
+    before do
+      @relation1 = Table.new(:users)
+      @relation2 = 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_not :mysql 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_not :mysql do
+            sql.should be_like(%Q{"users"."id" IS NULL})
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/arel/engines/sql/unit/predicates/in_spec.rb b/spec/arel/engines/sql/unit/predicates/in_spec.rb
new file mode 100644
index 0000000000..d3e75cfb84
--- /dev/null
+++ b/spec/arel/engines/sql/unit/predicates/in_spec.rb
@@ -0,0 +1,86 @@
+require File.join(File.dirname(__FILE__), '..', '..', '..', '..', '..', 'spec_helper')
+
+module Arel
+  describe In do
+    before do
+      @relation = 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_not :mysql 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_not :mysql do
+              sql.should be_like(%Q{"users"."id" IN (1, 2, 3)})
+            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_not :mysql do
+            sql.should be_like(%Q{"users"."id" BETWEEN 1 AND 2})
+          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_not :mysql do
+            sql.should be_like(%Q{
+              "users"."id" IN (SELECT "users"."id", "users"."name" FROM "users")
+            })
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/arel/engines/sql/unit/predicates/predicates_spec.rb b/spec/arel/engines/sql/unit/predicates/predicates_spec.rb
new file mode 100644
index 0000000000..d55e178e43
--- /dev/null
+++ b/spec/arel/engines/sql/unit/predicates/predicates_spec.rb
@@ -0,0 +1,65 @@
+require File.join(File.dirname(__FILE__), '..', '..', '..', '..', '..', 'spec_helper')
+
+module Arel
+  describe Predicate do
+    before do
+      @relation = Table.new(:users)
+      @attribute1 = @relation[:id]
+      @attribute2 = @relation[:name]
+      @operand1 = Equality.new(@attribute1, 1)
+      @operand2 = 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
+        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
+        end
+      end
+    end
+  end
+end
diff --git a/spec/arel/engines/sql/unit/primitives/attribute_spec.rb b/spec/arel/engines/sql/unit/primitives/attribute_spec.rb
new file mode 100644
index 0000000000..6cb72f3c19
--- /dev/null
+++ b/spec/arel/engines/sql/unit/primitives/attribute_spec.rb
@@ -0,0 +1,32 @@
+require File.join(File.dirname(__FILE__), '..', '..', '..', '..', '..', '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_not :mysql do
+            sql.should be_like(%Q{"users"."id"})
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/arel/engines/sql/unit/primitives/expression_spec.rb b/spec/arel/engines/sql/unit/primitives/expression_spec.rb
new file mode 100644
index 0000000000..ee7f2c1461
--- /dev/null
+++ b/spec/arel/engines/sql/unit/primitives/expression_spec.rb
@@ -0,0 +1,24 @@
+require File.join(File.dirname(__FILE__), '..', '..', '..', '..', '..', '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_not :mysql do
+          sql.should be_like(%Q{COUNT("users"."id") AS "alias"})
+        end
+      end
+    end
+  end
+end
diff --git a/spec/arel/engines/sql/unit/primitives/literal_spec.rb b/spec/arel/engines/sql/unit/primitives/literal_spec.rb
new file mode 100644
index 0000000000..c7ff1cf879
--- /dev/null
+++ b/spec/arel/engines/sql/unit/primitives/literal_spec.rb
@@ -0,0 +1,23 @@
+require File.join(File.dirname(__FILE__), '..', '..', '..', '..', '..', '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_not :mysql do
+          sql.should be_like(%Q{SELECT COUNT(*) AS count_id FROM "users"})
+        end
+      end
+    end
+  end
+end
diff --git a/spec/arel/engines/sql/unit/primitives/value_spec.rb b/spec/arel/engines/sql/unit/primitives/value_spec.rb
new file mode 100644
index 0000000000..ff3533f6ef
--- /dev/null
+++ b/spec/arel/engines/sql/unit/primitives/value_spec.rb
@@ -0,0 +1,29 @@
+require File.join(File.dirname(__FILE__), '..', '..', '..', '..', '..', '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/arel/engines/sql/unit/relations/alias_spec.rb b/spec/arel/engines/sql/unit/relations/alias_spec.rb
new file mode 100644
index 0000000000..b67a0bbc89
--- /dev/null
+++ b/spec/arel/engines/sql/unit/relations/alias_spec.rb
@@ -0,0 +1,43 @@
+require File.join(File.dirname(__FILE__), '..', '..', '..', '..', '..', '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_not :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
+        end
+      end
+    end
+  end
+end
diff --git a/spec/arel/engines/sql/unit/relations/delete_spec.rb b/spec/arel/engines/sql/unit/relations/delete_spec.rb
new file mode 100644
index 0000000000..7a5e2b0088
--- /dev/null
+++ b/spec/arel/engines/sql/unit/relations/delete_spec.rb
@@ -0,0 +1,63 @@
+require File.join(File.dirname(__FILE__), '..', '..', '..', '..', '..', '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_not :mysql 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_not :mysql 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_not :mysql do
+          sql.should be_like(%Q{
+            DELETE
+            FROM "users"
+            LIMIT 1
+          })
+        end
+      end
+    end
+  end
+end
diff --git a/spec/arel/engines/sql/unit/relations/group_spec.rb b/spec/arel/engines/sql/unit/relations/group_spec.rb
new file mode 100644
index 0000000000..5e0c675c8b
--- /dev/null
+++ b/spec/arel/engines/sql/unit/relations/group_spec.rb
@@ -0,0 +1,56 @@
+require File.join(File.dirname(__FILE__), '..', '..', '..', '..', '..', '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_not :mysql 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_not :mysql 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/arel/engines/sql/unit/relations/insert_spec.rb b/spec/arel/engines/sql/unit/relations/insert_spec.rb
new file mode 100644
index 0000000000..29a5e0bf42
--- /dev/null
+++ b/spec/arel/engines/sql/unit/relations/insert_spec.rb
@@ -0,0 +1,107 @@
+require File.join(File.dirname(__FILE__), '..', '..', '..', '..', '..', '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')
+          })
+        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')
+            })
+          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_not :mysql do
+            @insertion.to_sql.should be_like(%Q{
+              INSERT
+              INTO "users"
+              ("id") VALUES (1)
+            })
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/arel/engines/sql/unit/relations/join_spec.rb b/spec/arel/engines/sql/unit/relations/join_spec.rb
new file mode 100644
index 0000000000..f904b61870
--- /dev/null
+++ b/spec/arel/engines/sql/unit/relations/join_spec.rb
@@ -0,0 +1,57 @@
+require File.join(File.dirname(__FILE__), '..', '..', '..', '..', '..', 'spec_helper')
+
+module Arel
+  describe Join do
+    before do
+      @relation1 = Table.new(:users)
+      @relation2 = Table.new(:photos)
+      @predicate = @relation1[:id].eq(@relation2[: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, @predicate).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_not :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
+        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_not :mysql do
+            sql.should be_like(%Q{
+              SELECT "users"."id", "users"."name"
+              FROM "users"
+                INNER JOIN asdf ON fdsa
+            })
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/arel/engines/sql/unit/relations/order_spec.rb b/spec/arel/engines/sql/unit/relations/order_spec.rb
new file mode 100644
index 0000000000..ce97a4dd5e
--- /dev/null
+++ b/spec/arel/engines/sql/unit/relations/order_spec.rb
@@ -0,0 +1,113 @@
+require File.join(File.dirname(__FILE__), '..', '..', '..', '..', '..', '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_not :mysql 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_not :mysql 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_not :mysql 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_not :mysql 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/arel/engines/sql/unit/relations/project_spec.rb b/spec/arel/engines/sql/unit/relations/project_spec.rb
new file mode 100644
index 0000000000..5e29124cfa
--- /dev/null
+++ b/spec/arel/engines/sql/unit/relations/project_spec.rb
@@ -0,0 +1,110 @@
+require File.join(File.dirname(__FILE__), '..', '..', '..', '..', '..', '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_not :mysql 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_not :mysql 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_not :mysql 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_not :mysql 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_not :mysql 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/arel/engines/sql/unit/relations/skip_spec.rb b/spec/arel/engines/sql/unit/relations/skip_spec.rb
new file mode 100644
index 0000000000..c14bd1ce95
--- /dev/null
+++ b/spec/arel/engines/sql/unit/relations/skip_spec.rb
@@ -0,0 +1,32 @@
+require File.join(File.dirname(__FILE__), '..', '..', '..', '..', '..', '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_not :mysql do
+          sql.should be_like(%Q{
+            SELECT "users"."id", "users"."name"
+            FROM "users"
+            OFFSET 4
+          })
+        end
+      end
+    end
+  end
+end
diff --git a/spec/arel/engines/sql/unit/relations/table_spec.rb b/spec/arel/engines/sql/unit/relations/table_spec.rb
new file mode 100644
index 0000000000..9797b38822
--- /dev/null
+++ b/spec/arel/engines/sql/unit/relations/table_spec.rb
@@ -0,0 +1,69 @@
+require File.join(File.dirname(__FILE__), '..', '..', '..', '..', '..', '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_not :mysql 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 { stub(@relation.engine).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/arel/engines/sql/unit/relations/take_spec.rb b/spec/arel/engines/sql/unit/relations/take_spec.rb
new file mode 100644
index 0000000000..8f1240fc17
--- /dev/null
+++ b/spec/arel/engines/sql/unit/relations/take_spec.rb
@@ -0,0 +1,32 @@
+require File.join(File.dirname(__FILE__), '..', '..', '..', '..', '..', '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_not :mysql do
+          sql.should be_like(%Q{
+            SELECT "users"."id", "users"."name"
+            FROM "users"
+            LIMIT 4
+          })
+        end
+      end
+    end
+  end
+end
diff --git a/spec/arel/engines/sql/unit/relations/update_spec.rb b/spec/arel/engines/sql/unit/relations/update_spec.rb
new file mode 100644
index 0000000000..4d728eb241
--- /dev/null
+++ b/spec/arel/engines/sql/unit/relations/update_spec.rb
@@ -0,0 +1,151 @@
+require File.join(File.dirname(__FILE__), '..', '..', '..', '..', '..', 'spec_helper')
+
+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
+      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'
+            LIMIT 1
+          })
+        end
+
+        adapter_is :postgresql do
+          sql.should be_like(%Q{
+            UPDATE "users"
+            SET "name" = E'nick'
+            LIMIT 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
+        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_not :mysql 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
+        end
+      end
+    end
+
+  end
+end
diff --git a/spec/arel/engines/sql/unit/relations/where_spec.rb b/spec/arel/engines/sql/unit/relations/where_spec.rb
new file mode 100644
index 0000000000..4f0cce1e01
--- /dev/null
+++ b/spec/arel/engines/sql/unit/relations/where_spec.rb
@@ -0,0 +1,56 @@
+require File.join(File.dirname(__FILE__), '..', '..', '..', '..', '..', '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_not :mysql 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_not :mysql do
+            sql.should be_like(%Q{
+              SELECT "users"."id", "users"."name"
+              FROM "users"
+              WHERE asdf
+            })
+          end
+        end
+      end
+    end
+  end
+end