diff --git a/chain.go b/chain.go
index ed2b8012..1efb46d8 100644
--- a/chain.go
+++ b/chain.go
@@ -71,16 +71,6 @@ func (s *Chain) Model(model interface{}) *Chain {
 	return s
 }
 
-func (s *Chain) Where(querystring interface{}, args ...interface{}) *Chain {
-	s.whereClause = append(s.whereClause, map[string]interface{}{"query": querystring, "args": args})
-	return s
-}
-
-func (s *Chain) Not(querystring interface{}, args ...interface{}) *Chain {
-	s.notClause = append(s.notClause, map[string]interface{}{"query": querystring, "args": args})
-	return s
-}
-
 func (s *Chain) Limit(value interface{}) *Chain {
 	if str, err := getInterfaceAsString(value); err == nil {
 		s.limitStr = str
@@ -151,16 +141,6 @@ func (s *Chain) Exec(sql string) *Chain {
 	return s
 }
 
-func (s *Chain) First(out interface{}, where ...interface{}) *Chain {
-	s.do(out).where(where...).first()
-	return s
-}
-
-func (s *Chain) Last(out interface{}, where ...interface{}) *Chain {
-	s.do(out).where(where...).last()
-	return s
-}
-
 func (s *Chain) Attrs(attrs ...interface{}) *Chain {
 	s.initAttrs = append(s.initAttrs, toSearchableMap(attrs...))
 	return s
@@ -196,21 +176,11 @@ func (s *Chain) FirstOrCreate(out interface{}, where ...interface{}) *Chain {
 	return s
 }
 
-func (s *Chain) Find(out interface{}, where ...interface{}) *Chain {
-	s.do(out).where(where...).query()
-	return s
-}
-
 func (s *Chain) Pluck(column string, value interface{}) (orm *Chain) {
 	s.do(s.value).pluck(column, value)
 	return s
 }
 
-func (s *Chain) Or(querystring interface{}, args ...interface{}) *Chain {
-	s.orClause = append(s.orClause, map[string]interface{}{"query": querystring, "args": args})
-	return s
-}
-
 func (s *Chain) Unscoped() *Chain {
 	s.unscoped = true
 	return s
diff --git a/do.go b/do.go
index a1324adb..bb637e19 100644
--- a/do.go
+++ b/do.go
@@ -14,7 +14,7 @@ import (
 
 type Do struct {
 	chain              *Chain
-	db                 sqlCommon
+	db                 *DB
 	guessedTableName   string
 	specifiedTableName string
 	startedTransaction bool
@@ -732,6 +732,14 @@ func (s *Do) commit_or_rollback() {
 	}
 }
 
+func (s *Do) initialize() {
+	// TODO initializeWithSearchCondition
+}
+
+func (s *Do) updateAttrs_() {
+	// TODO return false if no updates
+}
+
 func (s *Do) initializeWithSearchCondition() {
 	for _, clause := range s.whereClause {
 		switch value := clause["query"].(type) {
diff --git a/errors.go b/errors.go
index 2c968dbf..e99a7f23 100644
--- a/errors.go
+++ b/errors.go
@@ -3,6 +3,8 @@ package gorm
 import "errors"
 
 var (
-	RecordNotFound = errors.New("Record Not Found")
-	InvalidSql     = errors.New("Invalid SQL")
+	RecordNotFound     = errors.New("Record Not Found")
+	InvalidSql         = errors.New("Invalid SQL")
+	NoNewAttrs         = errors.New("No new Attributes")
+	NoValidTransaction = errors.New("No valid transaction")
 )
diff --git a/main.go b/main.go
index 0f0ea4db..ef881a47 100644
--- a/main.go
+++ b/main.go
@@ -1,25 +1,29 @@
 package gorm
 
-import "database/sql"
+import (
+	"errors"
+
+	"database/sql"
+)
 import "github.com/jinzhu/gorm/dialect"
 
-var singularTableName bool
-var tagIdentifier string
-
-func init() {
-	tagIdentifier = "sql"
-}
-
 type DB struct {
-	db      sqlCommon
-	dialect dialect.Dialect
-	logger  Logger
-	logMode bool
+	db            sqlCommon
+	parent        *DB
+	search        *search
+	data          interface{}
+	Error         error
+	dialect       dialect.Dialect
+	tagIdentifier string
+	singularTable bool
+	logger        Logger
+	logMode       bool
 }
 
 func Open(driver, source string) (db DB, err error) {
 	db.db, err = sql.Open(driver, source)
 	db.dialect = dialect.New(driver)
+	db.parent = &db
 	return
 }
 
@@ -30,117 +34,231 @@ func (s *DB) SetPool(n int) {
 }
 
 func (s *DB) SetTagIdentifier(str string) {
-	tagIdentifier = str
+	s.parent.tagIdentifier = str
 }
 
 func (s *DB) SetLogger(l Logger) {
-	s.logger = l
+	s.parent.logger = l
 }
 
 func (s *DB) LogMode(b bool) {
-	s.logMode = b
+	s.parent.logMode = b
 }
 
-func (s *DB) SingularTable(result bool) {
-	singularTableName = result
+func (s *DB) SingularTable(b bool) {
+	s.parent.singularTable = b
 }
 
-func (s *DB) buildChain() *Chain {
-	return &Chain{db: s.db, d: s}
+func (s *DB) clone() *DB {
+	db := &DB{db: s.db, parent: s.parent, search: s.parent.search.clone()}
+	db.search.db = db
+	return db
 }
 
-func (s *DB) Where(querystring interface{}, args ...interface{}) *Chain {
-	return s.buildChain().Where(querystring, args...)
+func (s *DB) do(data interface{}) *Do {
+	s.data = data
+	return &Do{db: s}
 }
 
-func (s *DB) Not(querystring interface{}, args ...interface{}) *Chain {
-	return s.buildChain().Not(querystring, args...)
+func (s *DB) err(err error) error {
+	if err != nil {
+		s.Error = err
+		s.warn(err)
+	}
+	return err
 }
 
-func (s *DB) First(out interface{}, where ...interface{}) *Chain {
-	return s.buildChain().First(out, where...)
+func (s *DB) hasError() bool {
+	return s.Error != nil
 }
 
-func (s *DB) Last(out interface{}, where ...interface{}) *Chain {
-	return s.buildChain().Last(out, where...)
+func (s *DB) Where(query interface{}, args ...interface{}) *DB {
+	return s.clone().search.where(query, args...).db
 }
 
-func (s *DB) Attrs(attrs ...interface{}) *Chain {
-	return s.buildChain().Attrs(attrs...)
+func (s *DB) Or(query interface{}, args ...interface{}) *DB {
+	return s.clone().search.where(query, args...).db
 }
 
-func (s *DB) Assign(attrs ...interface{}) *Chain {
-	return s.buildChain().Assign(attrs...)
+func (s *DB) Not(query interface{}, args ...interface{}) *DB {
+	return s.clone().search.not(query, args...).db
 }
 
-func (s *DB) FirstOrInit(out interface{}, where ...interface{}) *Chain {
-	return s.buildChain().FirstOrInit(out, where...)
+func (s *DB) Limit(value interface{}) *DB {
+	return s.clone().search.limit(value).db
 }
 
-func (s *DB) FirstOrCreate(out interface{}, where ...interface{}) *Chain {
-	return s.buildChain().FirstOrCreate(out, where...)
+func (s *DB) Offset(value interface{}) *DB {
+	return s.clone().search.offset(value).db
 }
 
-func (s *DB) Find(out interface{}, where ...interface{}) *Chain {
-	return s.buildChain().Find(out, where...)
+func (s *DB) Order(value string, reorder ...bool) *DB {
+	return s.clone().search.order(value, reorder...).db
 }
 
-func (s *DB) Limit(value interface{}) *Chain {
-	return s.buildChain().Limit(value)
+func (s *DB) Select(value interface{}) *DB {
+	return s.clone().search.selects(value).db
 }
 
-func (s *DB) Offset(value interface{}) *Chain {
-	return s.buildChain().Offset(value)
+func (s *DB) Unscoped() *DB {
+	return s.clone().search.unscoped().db
 }
 
-func (s *DB) Order(value string, reorder ...bool) *Chain {
-	return s.buildChain().Order(value, reorder...)
+func (s *DB) First(out interface{}, where ...interface{}) *DB {
+	s.clone().search.limit(1).where(where[0], where[1:]).db.do(out).first()
+	return s
 }
 
-func (s *DB) Select(value interface{}) *Chain {
-	return s.buildChain().Select(value)
+func (s *DB) Last(out interface{}, where ...interface{}) *DB {
+	s.clone().search.limit(1).where(where[0], where[1:]).db.do(out).last()
+	return s
 }
 
-func (s *DB) Save(value interface{}) *Chain {
-	return s.buildChain().Save(value)
+func (s *DB) Find(out interface{}, where ...interface{}) *DB {
+	s.clone().search.where(where[0], where[1:]).db.do(out).query()
+	return s
 }
 
-func (s *DB) Delete(value interface{}) *Chain {
-	return s.buildChain().Delete(value)
+func (s *DB) Attrs(attrs ...interface{}) *DB {
+	return s.clone().search.attrs(attrs...).db
 }
 
-func (s *DB) Unscoped() *Chain {
-	return s.buildChain().Unscoped()
+func (s *DB) Assign(attrs ...interface{}) *DB {
+	return s.clone().search.assign(attrs...).db
 }
 
-func (s *DB) Exec(sql string) *Chain {
-	return s.buildChain().Exec(sql)
+func (s *DB) FirstOrInit(out interface{}, where ...interface{}) *DB {
+	if s.First(out, where...).Error != nil {
+		s.clone().do(out).where(where).initialize()
+	} else {
+		if len(s.search.assignAttrs) > 0 {
+			s.do(out).updateAttrs(s.assignAttrs) //updated or not
+		}
+	}
+	return s
 }
 
-func (s *DB) Model(value interface{}) *Chain {
-	return s.buildChain().Model(value)
+func (s *DB) FirstOrCreate(out interface{}, where ...interface{}) *DB {
+	if s.First(out, where...).Error != nil {
+		s.clone().do(out).where(where...).initialize()
+		s.Save(out)
+	} else {
+		if len(s.search.assignAttrs) > 0 {
+			s.do(out).updateAttrs(s.search.assignAttrs).update()
+		}
+	}
+	return s
 }
 
-func (s *DB) Table(name string) *Chain {
-	return s.buildChain().Table(name)
+func (s *DB) Save(value interface{}) *DB {
+	s.do(value).begin().save().commit_or_rollback()
+	return s
 }
 
-func (s *DB) CreateTable(value interface{}) *Chain {
-	return s.buildChain().CreateTable(value)
+func (s *DB) Delete(value interface{}) *DB {
+	s.do(value).bengin().delete(value).commit_or_rollback()
+	return s
 }
 
-func (s *DB) DropTable(value interface{}) *Chain {
-	return s.buildChain().DropTable(value)
+func (s *DB) Exec(sql string) *DB {
+	s.do(nil).exec(sql)
+	return s
 }
 
-func (s *DB) AutoMigrate(value interface{}) *Chain {
-	return s.buildChain().AutoMigrate(value)
+func (s *DB) Model(value interface{}) *DB {
+	c := s.clone()
+	c.data = value
+	return c
 }
 
-func (s *DB) Debug() *Chain {
-	return s.buildChain().Debug()
+func (s *DB) Related(value interface{}, foreign_keys ...string) *DB {
+	s.clone().do(value).related(s.value, foreign_keys...)
+	return s
 }
 
-func (s *DB) Begin() *Chain {
-	return s.buildChain().Begin()
+func (s *DB) Pluck(column string, value interface{}) *DB {
+	s.clone().search.selects(column).do(s.value).pluck(column, value)
+	return s
+}
+
+func (s *DB) Count(value interface{}) *DB {
+	s.clone().search.selects("count(*)").do(s.value).count(value)
+	return s
+}
+
+func (s *DB) Table(name string) *DB {
+	return s.clone().table(name).db
+}
+
+// Debug
+func (s *DB) Debug() *DB {
+	s.logMode = true
+	return s
+}
+
+// Transactions
+func (s *DB) Begin() *DB {
+	c := s.clone()
+	if db, ok := c.db.(sqlDb); ok {
+		tx, err := db.Begin()
+		c.db = interface{}(tx).(sqlCommon)
+		c.err(err)
+	} else {
+		c.err(errors.New("Can't start a transaction."))
+	}
+	return c
+}
+
+func (s *DB) Commit() *DB {
+	if db, ok := s.db.(sqlTx); ok {
+		s.err(db.Commit())
+	} else {
+		s.err(NoValidTransaction)
+	}
+	return s
+}
+
+func (s *DB) Rollback() *DB {
+	if db, ok := s.db.(sqlTx); ok {
+		s.err(db.Rollback())
+	} else {
+		s.err(NoValidTransaction)
+	}
+	return s
+}
+
+// Migrations
+func (s *DB) CreateTable(value interface{}) *DB {
+	s.do(value).createTable()
+	return s
+}
+
+func (s *DB) DropTable(value interface{}) *DB {
+	s.do(value).dropTable()
+	return s
+}
+
+func (s *DB) AutoMigrate(value interface{}) *DB {
+	s.do(value).autoMigrate()
+	return s
+}
+
+func (s *DB) UpdateColumn(column string, typ string) *DB {
+	s.do(s.data).updateColumn(column, typ)
+	return s
+}
+
+func (s *DB) DropColumn(column string) *DB {
+	s.do(s.data).dropColumn(column)
+	return s
+}
+
+func (s *DB) AddIndex(column string, index_name ...string) *DB {
+	s.do(s.data).addIndex(column, index_name...)
+	return s
+}
+
+func (s *DB) RemoveIndex(column string) *DB {
+	s.do(s.data).removeIndex(column)
+	return s
 }
diff --git a/search.go b/search.go
index bebf2c02..8345a033 100644
--- a/search.go
+++ b/search.go
@@ -3,6 +3,7 @@ package gorm
 import "strconv"
 
 type search struct {
+	db          *DB
 	whereClause []map[string]interface{}
 	orClause    []map[string]interface{}
 	notClause   []map[string]interface{}
@@ -12,6 +13,7 @@ type search struct {
 	selectStr   string
 	offsetStr   string
 	limitStr    string
+	tableName   string
 	unscope     bool
 }
 
@@ -90,6 +92,11 @@ func (s *search) unscoped() *search {
 	return s
 }
 
+func (s *search) table(name string) *search {
+	s.tableName = name
+	return s
+}
+
 func getInterfaceAsString(value interface{}) (str string, err error) {
 	switch value := value.(type) {
 	case string: