diff --git a/dialects/postgres/postgres.go b/dialects/postgres/postgres.go
index 37881090..adeeec7b 100644
--- a/dialects/postgres/postgres.go
+++ b/dialects/postgres/postgres.go
@@ -10,6 +10,7 @@ import (
 
 type Hstore map[string]*string
 
+// Value get value of Hstore
 func (h Hstore) Value() (driver.Value, error) {
 	hstore := hstore.Hstore{Map: map[string]sql.NullString{}}
 	if len(h) == 0 {
@@ -27,6 +28,7 @@ func (h Hstore) Value() (driver.Value, error) {
 	return hstore.Value()
 }
 
+// Scan scan value into Hstore
 func (h *Hstore) Scan(value interface{}) error {
 	hstore := hstore.Hstore{}
 
diff --git a/field.go b/field.go
index cadc1a72..87ef745b 100644
--- a/field.go
+++ b/field.go
@@ -56,36 +56,3 @@ func (field *Field) Set(value interface{}) (err error) {
 	field.IsBlank = isBlank(field.Field)
 	return nil
 }
-
-// Fields get value's fields
-func (scope *Scope) Fields() []*Field {
-	var (
-		fields             []*Field
-		indirectScopeValue = scope.IndirectValue()
-		isStruct           = indirectScopeValue.Kind() == reflect.Struct
-	)
-
-	for _, structField := range scope.GetModelStruct().StructFields {
-		if isStruct {
-			fieldValue := indirectScopeValue
-			for _, name := range structField.Names {
-				fieldValue = reflect.Indirect(fieldValue).FieldByName(name)
-			}
-			fields = append(fields, &Field{StructField: structField, Field: fieldValue, IsBlank: isBlank(fieldValue)})
-		} else {
-			fields = append(fields, &Field{StructField: structField, IsBlank: true})
-		}
-	}
-
-	return fields
-}
-
-func (scope *Scope) fieldsMap() map[string]*Field {
-	var results = map[string]*Field{}
-	for _, field := range scope.Fields() {
-		if field.IsNormal {
-			results[field.DBName] = field
-		}
-	}
-	return results
-}
diff --git a/polymorphic_test.go b/polymorphic_test.go
index 31ffab4a..df573f97 100644
--- a/polymorphic_test.go
+++ b/polymorphic_test.go
@@ -37,7 +37,7 @@ var compareToys = func(toys []Toy, contents []string) bool {
 
 func TestPolymorphic(t *testing.T) {
 	cat := Cat{Name: "Mr. Bigglesworth", Toy: Toy{Name: "cat toy"}}
-	dog := Dog{Name: "Pluto", Toys: []Toy{Toy{Name: "dog toy 1"}, Toy{Name: "dog toy 2"}}}
+	dog := Dog{Name: "Pluto", Toys: []Toy{{Name: "dog toy 1"}, {Name: "dog toy 2"}}}
 	DB.Save(&cat).Save(&dog)
 
 	if DB.Model(&cat).Association("Toy").Count() != 1 {
diff --git a/preload_test.go b/preload_test.go
index cde8e800..5c49ecc2 100644
--- a/preload_test.go
+++ b/preload_test.go
@@ -167,13 +167,13 @@ func TestNestedPreload2(t *testing.T) {
 		Level2s: []Level2{
 			{
 				Level1s: []*Level1{
-					&Level1{Value: "value1"},
-					&Level1{Value: "value2"},
+					{Value: "value1"},
+					{Value: "value2"},
 				},
 			},
 			{
 				Level1s: []*Level1{
-					&Level1{Value: "value3"},
+					{Value: "value3"},
 				},
 			},
 		},
@@ -265,8 +265,8 @@ func TestNestedPreload4(t *testing.T) {
 	want := Level3{
 		Level2: Level2{
 			Level1s: []Level1{
-				Level1{Value: "value1"},
-				Level1{Value: "value2"},
+				{Value: "value1"},
+				{Value: "value2"},
 			},
 		},
 	}
@@ -489,8 +489,8 @@ func TestNestedPreload8(t *testing.T) {
 	want[0] = Level3{
 		Level2: Level2{
 			Level1s: []Level1{
-				Level1{Value: "value1"},
-				Level1{Value: "value2"},
+				{Value: "value1"},
+				{Value: "value2"},
 			},
 		},
 	}
@@ -500,8 +500,8 @@ func TestNestedPreload8(t *testing.T) {
 	want[1] = Level3{
 		Level2: Level2{
 			Level1s: []Level1{
-				Level1{Value: "value3"},
-				Level1{Value: "value4"},
+				{Value: "value3"},
+				{Value: "value4"},
 			},
 		},
 	}
@@ -563,17 +563,17 @@ func TestNestedPreload9(t *testing.T) {
 	want[0] = Level3{
 		Level2: Level2{
 			Level1s: []Level1{
-				Level1{Value: "value1"},
-				Level1{Value: "value2"},
+				{Value: "value1"},
+				{Value: "value2"},
 			},
 		},
 		Level2_1: Level2_1{
 			Level1s: []Level1{
-				Level1{
+				{
 					Value:   "value1-1",
 					Level0s: []Level0{{Value: "Level0-1"}},
 				},
-				Level1{
+				{
 					Value:   "value2-2",
 					Level0s: []Level0{{Value: "Level0-2"}},
 				},
@@ -586,14 +586,14 @@ func TestNestedPreload9(t *testing.T) {
 	want[1] = Level3{
 		Level2: Level2{
 			Level1s: []Level1{
-				Level1{Value: "value3"},
-				Level1{Value: "value4"},
+				{Value: "value3"},
+				{Value: "value4"},
 			},
 		},
 		Level2_1: Level2_1{
 			Level1s: []Level1{
-				Level1{Value: "value3-3"},
-				Level1{Value: "value4-4"},
+				{Value: "value3-3"},
+				{Value: "value4-4"},
 			},
 		},
 	}
@@ -646,16 +646,16 @@ func TestNestedPreload10(t *testing.T) {
 	}
 
 	want := []*LevelA2{
-		&LevelA2{
+		{
 			Value: "bar",
 			LevelA3s: []*LevelA3{
-				&LevelA3{
+				{
 					Value:   "qux",
 					LevelA1: levelA1,
 				},
 			},
 		},
-		&LevelA2{
+		{
 			Value: "bar 2",
 		},
 	}
@@ -1151,11 +1151,11 @@ func TestNestedManyToManyPreload4(t *testing.T) {
 
 	dummy := Level1{
 		Value: "Level1",
-		Level2s: []*Level2{&Level2{
+		Level2s: []*Level2{{
 			Value: "Level2",
-			Level3s: []*Level3{&Level3{
+			Level3s: []*Level3{{
 				Value: "Level3",
-				Level4s: []*Level4{&Level4{
+				Level4s: []*Level4{{
 					Value: "Level4",
 				}},
 			}},
diff --git a/scope.go b/scope.go
index f8c9dec0..a5eedbac 100644
--- a/scope.go
+++ b/scope.go
@@ -23,7 +23,7 @@ type Scope struct {
 	instanceID      string
 	primaryKeyField *Field
 	skipLeft        bool
-	fields          map[string]*Field
+	fields          *[]*Field
 	selectAttrs     *[]string
 }
 
@@ -37,6 +37,15 @@ func (scope *Scope) New(value interface{}) *Scope {
 	return &Scope{db: scope.NewDB(), Search: &search{}, Value: value}
 }
 
+////////////////////////////////////////////////////////////////////////////////
+// Scope DB
+////////////////////////////////////////////////////////////////////////////////
+
+// DB return scope's DB connection
+func (scope *Scope) DB() *DB {
+	return scope.db
+}
+
 // NewDB create a new DB without search information
 func (scope *Scope) NewDB() *DB {
 	if scope.db != nil {
@@ -48,19 +57,14 @@ func (scope *Scope) NewDB() *DB {
 	return nil
 }
 
-// DB return scope's DB connection
-func (scope *Scope) DB() *DB {
-	return scope.db
-}
-
 // SQLDB return *sql.DB
 func (scope *Scope) SQLDB() sqlCommon {
 	return scope.db.db
 }
 
-// SkipLeft skip remaining callbacks
-func (scope *Scope) SkipLeft() {
-	scope.skipLeft = true
+// Dialect get dialect
+func (scope *Scope) Dialect() Dialect {
+	return scope.db.parent.dialect
 }
 
 // Quote used to quote string to escape them for database
@@ -76,18 +80,6 @@ func (scope *Scope) Quote(str string) string {
 	return scope.Dialect().Quote(str)
 }
 
-func (scope *Scope) quoteIfPossible(str string) string {
-	if regexp.MustCompile("^[a-zA-Z]+(.[a-zA-Z]+)*$").MatchString(str) {
-		return scope.Quote(str)
-	}
-	return str
-}
-
-// Dialect get dialect
-func (scope *Scope) Dialect() Dialect {
-	return scope.db.parent.dialect
-}
-
 // Err add error to Scope
 func (scope *Scope) Err(err error) error {
 	if err != nil {
@@ -96,14 +88,63 @@ func (scope *Scope) Err(err error) error {
 	return err
 }
 
+// HasError check if there are any error
+func (scope *Scope) HasError() bool {
+	return scope.db.Error != nil
+}
+
 // Log print log message
 func (scope *Scope) Log(v ...interface{}) {
 	scope.db.log(v...)
 }
 
-// HasError check if there are any error
-func (scope *Scope) HasError() bool {
-	return scope.db.Error != nil
+// SkipLeft skip remaining callbacks
+func (scope *Scope) SkipLeft() {
+	scope.skipLeft = true
+}
+
+// Fields get value's fields
+func (scope *Scope) Fields() []*Field {
+	if scope.fields == nil {
+		var (
+			fields             []*Field
+			indirectScopeValue = scope.IndirectValue()
+			isStruct           = indirectScopeValue.Kind() == reflect.Struct
+		)
+
+		for _, structField := range scope.GetModelStruct().StructFields {
+			if isStruct {
+				fieldValue := indirectScopeValue
+				for _, name := range structField.Names {
+					fieldValue = reflect.Indirect(fieldValue).FieldByName(name)
+				}
+				fields = append(fields, &Field{StructField: structField, Field: fieldValue, IsBlank: isBlank(fieldValue)})
+			} else {
+				fields = append(fields, &Field{StructField: structField, IsBlank: true})
+			}
+		}
+		scope.fields = &fields
+	}
+
+	return *scope.fields
+}
+
+// FieldByName find `gorm.Field` with field name or db name
+func (scope *Scope) FieldByName(name string) (field *Field, ok bool) {
+	var (
+		dbName           = ToDBName(name)
+		mostMatchedField *Field
+	)
+
+	for _, field := range scope.Fields() {
+		if field.Name == name || field.DBName == name {
+			return field, true
+		}
+		if field.DBName == dbName {
+			mostMatchedField = field
+		}
+	}
+	return mostMatchedField, mostMatchedField != nil
 }
 
 // PrimaryFields return scope's primary fields
@@ -195,35 +236,6 @@ func (scope *Scope) SetColumn(column interface{}, value interface{}) error {
 	return errors.New("could not convert column to field")
 }
 
-func (scope *Scope) callMethod(methodName string, reflectValue reflect.Value) {
-	if reflectValue.CanAddr() {
-		reflectValue = reflectValue.Addr()
-	}
-
-	if methodValue := reflectValue.MethodByName(methodName); methodValue.IsValid() {
-		switch method := methodValue.Interface().(type) {
-		case func():
-			method()
-		case func(*Scope):
-			method(scope)
-		case func(*DB):
-			newDB := scope.NewDB()
-			method(newDB)
-			scope.Err(newDB.Error)
-		case func() error:
-			scope.Err(method())
-		case func(*Scope) error:
-			scope.Err(method(scope))
-		case func(*DB) error:
-			newDB := scope.NewDB()
-			scope.Err(method(newDB))
-			scope.Err(newDB.Error)
-		default:
-			scope.Err(fmt.Errorf("unsupported function %v", methodName))
-		}
-	}
-}
-
 // CallMethod call scope value's method, if it is a slice, will call its element's method one by one
 func (scope *Scope) CallMethod(methodName string) {
 	if scope.Value == nil {
@@ -253,6 +265,31 @@ func (scope *Scope) AddToVars(value interface{}) string {
 	return scope.Dialect().BindVar(len(scope.SQLVars))
 }
 
+// SelectAttrs return selected attributes
+func (scope *Scope) SelectAttrs() []string {
+	if scope.selectAttrs == nil {
+		attrs := []string{}
+		for _, value := range scope.Search.selects {
+			if str, ok := value.(string); ok {
+				attrs = append(attrs, str)
+			} else if strs, ok := value.([]string); ok {
+				attrs = append(attrs, strs...)
+			} else if strs, ok := value.([]interface{}); ok {
+				for _, str := range strs {
+					attrs = append(attrs, fmt.Sprintf("%v", str))
+				}
+			}
+		}
+		scope.selectAttrs = &attrs
+	}
+	return *scope.selectAttrs
+}
+
+// OmitAttrs return omitted attributes
+func (scope *Scope) OmitAttrs() []string {
+	return scope.Search.omits
+}
+
 type tabler interface {
 	TableName() string
 }
@@ -296,24 +333,6 @@ func (scope *Scope) CombinedConditionSql() string {
 		scope.havingSQL() + scope.orderSQL() + scope.limitAndOffsetSQL()
 }
 
-// FieldByName find `gorm.Field` with field name or db name
-func (scope *Scope) FieldByName(name string) (field *Field, ok bool) {
-	var (
-		dbName           = ToDBName(name)
-		mostMatchedField *Field
-	)
-
-	for _, field := range scope.Fields() {
-		if field.Name == name || field.DBName == name {
-			return field, true
-		}
-		if field.DBName == dbName {
-			mostMatchedField = field
-		}
-	}
-	return mostMatchedField, mostMatchedField != nil
-}
-
 // Raw set raw sql
 func (scope *Scope) Raw(sql string) *Scope {
 	scope.SQL = strings.Replace(sql, "$$", "?", -1)
@@ -389,35 +408,56 @@ func (scope *Scope) CommitOrRollback() *Scope {
 	return scope
 }
 
-// SelectAttrs return selected attributes
-func (scope *Scope) SelectAttrs() []string {
-	if scope.selectAttrs == nil {
-		attrs := []string{}
-		for _, value := range scope.Search.selects {
-			if str, ok := value.(string); ok {
-				attrs = append(attrs, str)
-			} else if strs, ok := value.([]string); ok {
-				attrs = append(attrs, strs...)
-			} else if strs, ok := value.([]interface{}); ok {
-				for _, str := range strs {
-					attrs = append(attrs, fmt.Sprintf("%v", str))
-				}
-			}
-		}
-		scope.selectAttrs = &attrs
-	}
-	return *scope.selectAttrs
-}
-
-// OmitAttrs return omitted attributes
-func (scope *Scope) OmitAttrs() []string {
-	return scope.Search.omits
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 // Private Methods For *gorm.Scope
 ////////////////////////////////////////////////////////////////////////////////
 
+func (scope *Scope) fieldsMap() map[string]*Field {
+	var results = map[string]*Field{}
+	for _, field := range scope.Fields() {
+		if field.IsNormal {
+			results[field.DBName] = field
+		}
+	}
+	return results
+}
+
+func (scope *Scope) callMethod(methodName string, reflectValue reflect.Value) {
+	if reflectValue.CanAddr() {
+		reflectValue = reflectValue.Addr()
+	}
+
+	if methodValue := reflectValue.MethodByName(methodName); methodValue.IsValid() {
+		switch method := methodValue.Interface().(type) {
+		case func():
+			method()
+		case func(*Scope):
+			method(scope)
+		case func(*DB):
+			newDB := scope.NewDB()
+			method(newDB)
+			scope.Err(newDB.Error)
+		case func() error:
+			scope.Err(method())
+		case func(*Scope) error:
+			scope.Err(method(scope))
+		case func(*DB) error:
+			newDB := scope.NewDB()
+			scope.Err(method(newDB))
+			scope.Err(newDB.Error)
+		default:
+			scope.Err(fmt.Errorf("unsupported function %v", methodName))
+		}
+	}
+}
+
+func (scope *Scope) quoteIfPossible(str string) string {
+	if regexp.MustCompile("^[a-zA-Z]+(.[a-zA-Z]+)*$").MatchString(str) {
+		return scope.Quote(str)
+	}
+	return str
+}
+
 func (scope *Scope) scan(rows *sql.Rows, columns []string, fieldsMap map[string]*Field) {
 	var values = make([]interface{}, len(columns))
 	var ignored interface{}
@@ -448,6 +488,7 @@ func (scope *Scope) scan(rows *sql.Rows, columns []string, fieldsMap map[string]
 		}
 	}
 }
+
 func (scope *Scope) primaryCondition(value interface{}) string {
 	return fmt.Sprintf("(%v = %v)", scope.Quote(scope.PrimaryKey()), value)
 }
diff --git a/utils.go b/utils.go
index af11f5d2..c525631c 100644
--- a/utils.go
+++ b/utils.go
@@ -134,7 +134,7 @@ func toQueryMarks(primaryValues [][]interface{}) string {
 
 	for _, primaryValue := range primaryValues {
 		var marks []string
-		for _ = range primaryValue {
+		for range primaryValue {
 			marks = append(marks, "?")
 		}