Only update non blank fields that has been changed

association.go

@@ -177,7 +177,7 @@ func (association *Association) Delete(values ...interface{}) *Association {
 			modelValue := reflect.New(scope.GetModelStruct().ModelType).Interface()
 			if results := newDB.Model(modelValue).UpdateColumn(foreignKeyMap); results.Error == nil {
 				if results.RowsAffected > 0 {
-					scope.updatedAttrsWithValues(foreignKeyMap, false)
+					scope.updatedAttrsWithValues(foreignKeyMap)
 				}
 			} else {
 				association.setErr(results.Error)

callback_update.go

@@ -22,17 +22,10 @@ func init() {
 func assignUpdatingAttributesCallback(scope *Scope) {
 	if attrs, ok := scope.InstanceGet("gorm:update_interface"); ok {
 		if maps := convertInterfaceToMap(attrs); len(maps) > 0 {
-			protected, ok := scope.Get("gorm:ignore_protected_attrs")
-			_, updateColumn := scope.Get("gorm:update_column")
-			updateAttrs, hasUpdate := scope.updatedAttrsWithValues(maps, ok && protected.(bool))
-
-			if updateColumn {
-				scope.InstanceSet("gorm:update_attrs", maps)
-			} else if len(updateAttrs) > 0 {
-				scope.InstanceSet("gorm:update_attrs", updateAttrs)
-			} else if !hasUpdate {
+			if updateMaps, hasUpdate := scope.updatedAttrsWithValues(maps); hasUpdate {
+				scope.InstanceSet("gorm:update_attrs", updateMaps)
+			} else {
 				scope.SkipLeft()
-				return
 			}
 		}
 	}
@@ -64,13 +57,7 @@ func updateCallback(scope *Scope) {
 
 		if updateAttrs, ok := scope.InstanceGet("gorm:update_attrs"); ok {
 			for column, value := range updateAttrs.(map[string]interface{}) {
-				if field, ok := scope.FieldByName(column); ok {
-					if scope.changeableField(field) {
-						sqls = append(sqls, fmt.Sprintf("%v = %v", scope.Quote(field.DBName), scope.AddToVars(value)))
-					}
-				} else {
-					sqls = append(sqls, fmt.Sprintf("%v = %v", scope.Quote(column), scope.AddToVars(value)))
-				}
+				sqls = append(sqls, fmt.Sprintf("%v = %v", scope.Quote(column), scope.AddToVars(value)))
 			}
 		} else {
 			fields := scope.Fields()

main.go

@@ -258,7 +258,7 @@ func (s *DB) FirstOrInit(out interface{}, where ...interface{}) *DB {
 		}
 		c.NewScope(out).inlineCondition(where...).initialize()
 	} else {
-		c.NewScope(out).updatedAttrsWithValues(convertInterfaceToMap(c.search.assignAttrs), false)
+		c.NewScope(out).updatedAttrsWithValues(convertInterfaceToMap(c.search.assignAttrs))
 	}
 	return c
 }

scope.go

@@ -154,20 +154,29 @@ func (scope *Scope) HasColumn(column string) bool {
 
 // SetColumn to set the column's value
 func (scope *Scope) SetColumn(column interface{}, value interface{}) error {
+	var updateAttrs = map[string]interface{}{}
+	if attrs, ok := scope.InstanceGet("gorm:update_attrs"); ok {
+		updateAttrs = attrs.(map[string]interface{})
+		defer scope.InstanceSet("gorm:update_attrs", updateAttrs)
+	}
+
 	if field, ok := column.(*Field); ok {
+		updateAttrs[field.DBName] = value
 		return field.Set(value)
 	} else if name, ok := column.(string); ok {
-
 		if field, ok := scope.Fields()[name]; ok {
+			updateAttrs[field.DBName] = value
 			return field.Set(value)
 		}
 
 		dbName := ToDBName(name)
 		if field, ok := scope.Fields()[dbName]; ok {
+			updateAttrs[field.DBName] = value
 			return field.Set(value)
 		}
 
 		if field, ok := scope.FieldByName(name); ok {
+			updateAttrs[field.DBName] = value
 			return field.Set(value)
 		}
 	}

scope_private.go

@@ -319,37 +319,29 @@ func (scope *Scope) callCallbacks(funcs []*func(s *Scope)) *Scope {
 	return scope
 }
 
-func (scope *Scope) updatedAttrsWithValues(values map[string]interface{}, ignoreProtectedAttrs bool) (results map[string]interface{}, hasUpdate bool) {
-	if !scope.IndirectValue().CanAddr() {
+func (scope *Scope) updatedAttrsWithValues(values map[string]interface{}) (results map[string]interface{}, hasUpdate bool) {
+	if scope.IndirectValue().Kind() != reflect.Struct {
 		return values, true
 	}
 
-	var hasExpr bool
+	results = map[string]interface{}{}
 	for key, value := range values {
-		if field, ok := scope.FieldByName(key); ok && field.Field.IsValid() {
+		if field, ok := scope.FieldByName(key); ok && scope.changeableField(field) {
 			if !reflect.DeepEqual(field.Field, reflect.ValueOf(value)) {
-				if _, ok := value.(*expr); ok {
-					hasExpr = true
-				} else if !equalAsString(field.Field.Interface(), value) {
-					hasUpdate = true
-					field.Set(value)
-				}
-			}
-		}
-	}
-
-	if hasExpr {
-		var updateMap = map[string]interface{}{}
-		for key, field := range scope.Fields() {
-			if field.IsNormal {
-				if v, ok := values[key]; ok {
-					updateMap[key] = v
+				if field.IsNormal {
+					if _, ok := value.(*expr); ok {
+						hasUpdate = true
+						results[field.DBName] = value
+					} else if !equalAsString(field.Field.Interface(), value) {
+						hasUpdate = true
+						field.Set(value)
+						results[field.DBName] = field.Field.Interface()
+					}
 				} else {
-					updateMap[key] = field.Field.Interface()
+					field.Set(value)
 				}
 			}
 		}
-		return updateMap, true
 	}
 	return
 }
@@ -370,10 +362,10 @@ func (scope *Scope) rows() (*sql.Rows, error) {
 
 func (scope *Scope) initialize() *Scope {
 	for _, clause := range scope.Search.whereConditions {
-		scope.updatedAttrsWithValues(convertInterfaceToMap(clause["query"]), false)
+		scope.updatedAttrsWithValues(convertInterfaceToMap(clause["query"]))
 	}
-	scope.updatedAttrsWithValues(convertInterfaceToMap(scope.Search.initAttrs), false)
-	scope.updatedAttrsWithValues(convertInterfaceToMap(scope.Search.assignAttrs), false)
+	scope.updatedAttrsWithValues(convertInterfaceToMap(scope.Search.initAttrs))
+	scope.updatedAttrsWithValues(convertInterfaceToMap(scope.Search.assignAttrs))
 	return scope
 }
 

update_test.go

@@ -71,13 +71,14 @@ func TestUpdate(t *testing.T) {
 	}
 
 	DB.First(&product4, product4.Id)
+	updatedAt4 := product4.UpdatedAt
 	DB.Model(&product4).Update("price", gorm.Expr("price + ? - ?", 100, 50))
 	var product5 Product
 	DB.First(&product5, product4.Id)
 	if product5.Price != product4.Price+100-50 {
 		t.Errorf("Update with expression")
 	}
-	if product5.UpdatedAt.Format(time.RFC3339Nano) == product4.UpdatedAt.Format(time.RFC3339Nano) {
+	if product4.UpdatedAt.Format(time.RFC3339Nano) == updatedAt4.Format(time.RFC3339Nano) {
 		t.Errorf("Update with expression should update UpdatedAt")
 	}
 }
@@ -170,13 +171,15 @@ func TestUpdates(t *testing.T) {
 		t.Errorf("product2's code should be updated")
 	}
 
+	updatedAt4 := product4.UpdatedAt
 	DB.Model(&product4).Updates(map[string]interface{}{"price": gorm.Expr("price + ?", 100)})
 	var product5 Product
 	DB.First(&product5, product4.Id)
 	if product5.Price != product4.Price+100 {
 		t.Errorf("Updates with expression")
 	}
-	if product5.UpdatedAt.Format(time.RFC3339Nano) == product4.UpdatedAt.Format(time.RFC3339Nano) {
+	// product4's UpdatedAt will be reset when updating
+	if product4.UpdatedAt.Format(time.RFC3339Nano) == updatedAt4.Format(time.RFC3339Nano) {
 		t.Errorf("Updates with expression should update UpdatedAt")
 	}
 }
@@ -421,8 +424,6 @@ func TestUpdateColumnsSkipsAssociations(t *testing.T) {
 }
 
 func TestUpdatesWithBlankValues(t *testing.T) {
-	t.Skip("not implemented")
-
 	product := Product{Code: "product1", Price: 10}
 	DB.Save(&product)
 

utils.go

@@ -192,9 +192,7 @@ func convertInterfaceToMap(values interface{}) map[string]interface{} {
 
 	switch value := values.(type) {
 	case map[string]interface{}:
-		for k, v := range value {
-			attrs[k] = v
-		}
+		return value
 	case []interface{}:
 		for _, v := range value {
 			for key, value := range convertInterfaceToMap(v) {