diff --git a/do.go b/do.go
index cfc8a181..d7518487 100644
--- a/do.go
+++ b/do.go
@@ -14,6 +14,7 @@ import (
 
 type Do struct {
 	db                   *DB
+	search               *search
 	model                *Model
 	tableName            string
 	value                interface{}
@@ -27,10 +28,10 @@ type Do struct {
 
 func (s *Do) table() string {
 	if len(s.tableName) == 0 {
-		if len(s.db.search.tableName) == 0 {
+		if len(s.search.tableName) == 0 {
 			s.tableName = s.model.tableName()
 		} else {
-			s.tableName = s.db.search.tableName
+			s.tableName = s.search.tableName
 		}
 	}
 	return s.tableName
@@ -46,6 +47,11 @@ func (s *Do) err(err error) error {
 func (s *Do) setModel(value interface{}) *Do {
 	s.model = &Model{data: value, do: s}
 	s.value = value
+	if s.db.search == nil {
+		s.search = &search{}
+	} else {
+		s.search = s.db.search
+	}
 	return s
 }
 
@@ -191,10 +197,12 @@ func (s *Do) create() (i interface{}) {
 }
 
 func (s *Do) updateAttrs(values interface{}, ignore_protected_attrs ...bool) *Do {
+	ignore_protected := len(ignore_protected_attrs) > 0 && ignore_protected_attrs[0]
+
 	switch value := values.(type) {
 	case map[string]interface{}:
 		if len(value) > 0 {
-			results, has_update := s.model.updatedColumnsAndValues(value)
+			results, has_update := s.model.updatedColumnsAndValues(value, ignore_protected)
 			if len(results) > 0 {
 				s.update_attrs = results
 			} else if has_update {
@@ -218,16 +226,9 @@ func (s *Do) updateAttrs(values interface{}, ignore_protected_attrs ...bool) *Do
 	return s
 }
 
-func (s *Do) prepareUpdateAttrs() (results map[string]interface{}, update bool) {
-	if len(s.updateAttrs) > 0 {
-		results, update = s.model.updatedColumnsAndValues(s.updateAttrs)
-	}
-	return
-}
-
-func (s *Do) prepareUpdateSql(results map[string]interface{}) {
+func (s *Do) prepareUpdateSql() {
 	var sqls []string
-	for key, value := range results {
+	for key, value := range s.update_attrs {
 		sqls = append(sqls, fmt.Sprintf("%v = %v", key, s.addToVars(value)))
 	}
 
@@ -245,19 +246,11 @@ func (s *Do) prepareUpdateSql(results map[string]interface{}) {
 }
 
 func (s *Do) update() *Do {
-	update_attrs := s.updateAttrs
-	if len(update_attrs) > 0 {
-		var need_update bool
-		if update_attrs, need_update = s.prepareUpdateAttrs(); !need_update {
-			return s
-		}
-	}
-
 	s.model.callMethod("BeforeUpdate")
 	s.model.callMethod("BeforeSave")
-
 	s.saveBeforeAssociations()
-	s.prepareUpdateSql(update_attrs)
+
+	s.prepareUpdateSql()
 
 	if !s.db.hasError() {
 		s.exec()
@@ -274,7 +267,7 @@ func (s *Do) delete() *Do {
 	s.model.callMethod("BeforeDelete")
 
 	if !s.db.hasError() {
-		if !s.unscoped && s.model.hasColumn("DeletedAt") {
+		if !s.search.unscope && s.model.hasColumn("DeletedAt") {
 			s.sql = fmt.Sprintf("UPDATE %v SET deleted_at=%v %v", s.table(), s.addToVars(time.Now()), s.combinedSql())
 		} else {
 			s.sql = fmt.Sprintf("DELETE FROM %v %v", s.table(), s.combinedSql())
@@ -291,14 +284,12 @@ func (s *Do) prepareQuerySql() {
 }
 
 func (s *Do) first() {
-	s.limitStr = "1"
-	s.orderStrs = append(s.orderStrs, s.model.primaryKeyDb())
+	s.search.order(s.model.primaryKeyDb()).limit(1)
 	s.query()
 }
 
 func (s *Do) last() {
-	s.limitStr = "1"
-	s.orderStrs = append(s.orderStrs, s.model.primaryKeyDb()+" DESC")
+	s.search.order(s.model.primaryKeyDb() + " DESC").limit(1)
 	s.query()
 }
 
@@ -355,7 +346,7 @@ func (s *Do) query() {
 		is_slice = true
 		dest_type = dest_out.Type().Elem()
 	} else {
-		s.limitStr = "1"
+		s.search.limit(1)
 	}
 
 	s.prepareQuerySql()
@@ -411,7 +402,6 @@ func (s *Do) count(value interface{}) {
 }
 
 func (s *Do) pluck(column string, value interface{}) {
-	s.selectStr = column
 	dest_out := reflect.Indirect(reflect.ValueOf(value))
 
 	if dest_out.Kind() != reflect.Slice {
@@ -437,13 +427,6 @@ func (s *Do) pluck(column string, value interface{}) {
 	}
 }
 
-func (s *Do) where(where ...interface{}) *Do {
-	if len(where) > 0 {
-		s.whereClause = append(s.whereClause, map[string]interface{}{"query": where[0], "args": where[1:len(where)]})
-	}
-	return s
-}
-
 func (s *Do) primaryCondiation(value interface{}) string {
 	return fmt.Sprintf("(%v = %v)", s.model.primaryKeyDb(), value)
 }
@@ -561,7 +544,7 @@ func (s *Do) buildNotCondition(clause map[string]interface{}) (str string) {
 func (s *Do) whereSql() (sql string) {
 	var primary_condiations, and_conditions, or_conditions []string
 
-	if !s.unscoped && s.model.hasColumn("DeletedAt") {
+	if !s.search.unscope && s.model.hasColumn("DeletedAt") {
 		primary_condiations = append(primary_condiations, "(deleted_at IS NULL OR deleted_at <= '0001-01-02')")
 	}
 
@@ -569,15 +552,15 @@ func (s *Do) whereSql() (sql string) {
 		primary_condiations = append(primary_condiations, s.primaryCondiation(s.addToVars(s.model.primaryKeyValue())))
 	}
 
-	for _, clause := range s.whereClause {
+	for _, clause := range s.search.whereClause {
 		and_conditions = append(and_conditions, s.buildWhereCondition(clause))
 	}
 
-	for _, clause := range s.orClause {
+	for _, clause := range s.search.orClause {
 		or_conditions = append(or_conditions, s.buildWhereCondition(clause))
 	}
 
-	for _, clause := range s.notClause {
+	for _, clause := range s.search.notClause {
 		and_conditions = append(and_conditions, s.buildNotCondition(clause))
 	}
 
@@ -603,34 +586,34 @@ func (s *Do) whereSql() (sql string) {
 }
 
 func (s *Do) selectSql() string {
-	if len(s.selectStr) == 0 {
+	if len(s.search.selectStr) == 0 {
 		return "*"
 	} else {
-		return s.selectStr
+		return s.search.selectStr
 	}
 }
 
 func (s *Do) orderSql() string {
-	if len(s.orderStrs) == 0 {
+	if len(s.search.orders) == 0 {
 		return ""
 	} else {
-		return " ORDER BY " + strings.Join(s.orderStrs, ",")
+		return " ORDER BY " + strings.Join(s.search.orders, ",")
 	}
 }
 
 func (s *Do) limitSql() string {
-	if len(s.limitStr) == 0 {
+	if len(s.search.limitStr) == 0 {
 		return ""
 	} else {
-		return " LIMIT " + s.limitStr
+		return " LIMIT " + s.search.limitStr
 	}
 }
 
 func (s *Do) offsetSql() string {
-	if len(s.offsetStr) == 0 {
+	if len(s.search.offsetStr) == 0 {
 		return ""
 	} else {
-		return " OFFSET " + s.offsetStr
+		return " OFFSET " + s.search.offsetStr
 	}
 }
 
@@ -733,16 +716,19 @@ func (s *Do) commit_or_rollback() {
 	}
 }
 
+func (s *Do) where(where ...interface{}) *Do {
+	if len(where) > 0 {
+		s.search.where(where[0], where[1:])
+	}
+	return s
+}
+
 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 {
+	for _, clause := range s.search.whereClause {
 		switch value := clause["query"].(type) {
 		case map[string]interface{}:
 			for k, v := range value {
diff --git a/main.go b/main.go
index 512a6f48..7978eb4b 100644
--- a/main.go
+++ b/main.go
@@ -82,17 +82,17 @@ func (s *DB) Unscoped() *DB {
 }
 
 func (s *DB) First(out interface{}, where ...interface{}) *DB {
-	s.clone().search.limit(1).where(where[0], where[1:]).db.do(out).first()
+	s.clone().do(out).where(where...).first()
 	return s
 }
 
 func (s *DB) Last(out interface{}, where ...interface{}) *DB {
-	s.clone().search.limit(1).where(where[0], where[1:]).db.do(out).last()
+	s.clone().do(out).where(where...).last()
 	return s
 }
 
 func (s *DB) Find(out interface{}, where ...interface{}) *DB {
-	s.clone().search.where(where[0], where[1:]).db.do(out).query()
+	s.clone().do(out).where(where...).query()
 	return s
 }
 
diff --git a/model.go b/model.go
index 71f17429..3aa39287 100644
--- a/model.go
+++ b/model.go
@@ -100,7 +100,7 @@ func (m *Model) columnsHasValue(operation string) (fields []*Field) {
 	return
 }
 
-func (m *Model) updatedColumnsAndValues(values map[string]interface{}) (results map[string]interface{}, any_updated bool) {
+func (m *Model) updatedColumnsAndValues(values map[string]interface{}, ignore_protected_attrs bool) (results map[string]interface{}, any_updated bool) {
 	if m.data == nil {
 		return values, true
 	}
diff --git a/private.go b/private.go
index 565c7665..82248ad0 100644
--- a/private.go
+++ b/private.go
@@ -13,7 +13,9 @@ func (s *DB) clone() *DB {
 
 func (s *DB) do(data interface{}) *Do {
 	s.data = data
-	return &Do{db: s}.setModel(data)
+	do := Do{db: s}
+	do.setModel(data)
+	return &do
 }
 
 func (s *DB) err(err error) error {