diff --git a/association.go b/association.go
index 62d638b6..911626ab 100644
--- a/association.go
+++ b/association.go
@@ -53,14 +53,12 @@ func (association *Association) getPrimaryKeys(values ...interface{}) []interfac
 		reflectValue := reflect.Indirect(reflect.ValueOf(value))
 		if reflectValue.Kind() == reflect.Slice {
 			for i := 0; i < reflectValue.Len(); i++ {
-				primaryField := scope.New(reflectValue.Index(i).Interface()).PrimaryKeyField()
-				if !primaryField.IsBlank {
+				if primaryField := scope.New(reflectValue.Index(i).Interface()).PrimaryKeyField(); !primaryField.IsBlank {
 					primaryKeys = append(primaryKeys, primaryField.Field.Interface())
 				}
 			}
 		} else if reflectValue.Kind() == reflect.Struct {
-			primaryField := scope.New(value).PrimaryKeyField()
-			if !primaryField.IsBlank {
+			if primaryField := scope.New(value).PrimaryKeyField(); !primaryField.IsBlank {
 				primaryKeys = append(primaryKeys, primaryField.Field.Interface())
 			}
 		}
@@ -144,9 +142,7 @@ func (association *Association) Count() int {
 	count := -1
 	relationship := association.Field.Relationship
 	scope := association.Scope
-	field := association.Field.Field
-	fieldValue := field.Interface()
-	newScope := scope.New(fieldValue)
+	newScope := scope.New(association.Field.Field.Interface())
 
 	if relationship.Kind == "many_to_many" {
 		whereSql := fmt.Sprintf("%v.%v IN (SELECT %v.%v FROM %v WHERE %v.%v = ?)",
diff --git a/callback_create.go b/callback_create.go
index 52e9369c..fe0ba28d 100644
--- a/callback_create.go
+++ b/callback_create.go
@@ -25,7 +25,7 @@ func Create(scope *Scope) {
 		// set create sql
 		var sqls, columns []string
 		for _, field := range scope.Fields() {
-			if field.IsNormal && (!field.IsPrimaryKey || !scope.PrimaryKeyZero()) {
+			if (field.IsNormal && !field.IsPrimaryKey) || (field.IsPrimaryKey && !field.IsBlank) {
 				if field.DefaultValue != nil && field.IsBlank {
 					continue
 				}
@@ -35,8 +35,9 @@ func Create(scope *Scope) {
 		}
 
 		returningKey := "*"
-		if scope.PrimaryKey() != "" {
-			returningKey = scope.Quote(scope.PrimaryKey())
+		primaryField := scope.PrimaryKeyField()
+		if primaryField != nil {
+			returningKey = scope.Quote(primaryField.DBName)
 		}
 
 		if len(columns) == 0 {
@@ -64,19 +65,17 @@ func Create(scope *Scope) {
 				}
 			}
 		} else {
-			if scope.PrimaryKey() == "" {
+			if primaryField == nil {
 				if results, err := scope.DB().Exec(scope.Sql, scope.SqlVars...); err != nil {
 					scope.db.RowsAffected, _ = results.RowsAffected()
 				}
-			} else {
-				if scope.Err(scope.DB().QueryRow(scope.Sql, scope.SqlVars...).Scan(&id)) == nil {
-					scope.db.RowsAffected = 1
-				}
+			} else if scope.Err(scope.DB().QueryRow(scope.Sql, scope.SqlVars...).Scan(&id)) == nil {
+				scope.db.RowsAffected = 1
 			}
 		}
 
-		if scope.PrimaryKey() != "" && !scope.HasError() && scope.PrimaryKeyZero() {
-			scope.SetColumn(scope.PrimaryKey(), id)
+		if primaryField != nil && primaryField.IsBlank && !scope.HasError() {
+			scope.SetColumn(primaryField, id)
 		}
 	}
 }
diff --git a/callback_query.go b/callback_query.go
index 1333bcb4..c3671f12 100644
--- a/callback_query.go
+++ b/callback_query.go
@@ -46,9 +46,9 @@ func Query(scope *Scope) {
 		if scope.Err(err) != nil {
 			return
 		}
+		defer rows.Close()
 
 		columns, _ := rows.Columns()
-		defer rows.Close()
 		for rows.Next() {
 			scope.db.RowsAffected++
 
diff --git a/callback_shared.go b/callback_shared.go
index 5e501c4c..a00e0fb3 100644
--- a/callback_shared.go
+++ b/callback_shared.go
@@ -17,27 +17,11 @@ func CommitOrRollbackTransaction(scope *Scope) {
 func SaveBeforeAssociations(scope *Scope) {
 	for _, field := range scope.Fields() {
 		if !field.IsBlank && !field.IsIgnored {
-			relationship := field.Relationship
-			if relationship != nil && relationship.Kind == "belongs_to" {
+			if relationship := field.Relationship; relationship != nil && relationship.Kind == "belongs_to" {
 				value := field.Field
-				newDB := scope.NewDB()
-
-				if !value.CanAddr() {
-					// If can't take address, then clone the value and set it back
-					value = reflect.New(value.Type()).Elem()
-					for _, f := range newDB.NewScope(field.Field.Addr().Interface()).Fields() {
-						value.FieldByName(f.Name).Set(reflect.ValueOf(f.Field.Interface()))
-					}
-					scope.SetColumn(field, value.Interface())
-				}
-				scope.Err(newDB.Save(value.Addr().Interface()).Error)
-
+				scope.Err(scope.NewDB().Save(value.Addr().Interface()).Error)
 				if relationship.ForeignFieldName != "" {
-					scope.SetColumn(relationship.ForeignFieldName, newDB.NewScope(value.Addr().Interface()).PrimaryKeyValue())
-				}
-				if relationship.ForeignType != "" {
-					scope.Err(fmt.Errorf("gorm does not support polymorphic belongs_to associations"))
-					return
+					scope.SetColumn(relationship.ForeignFieldName, scope.New(value.Addr().Interface()).PrimaryKeyValue())
 				}
 			}
 		}
@@ -47,8 +31,7 @@ func SaveBeforeAssociations(scope *Scope) {
 func SaveAfterAssociations(scope *Scope) {
 	for _, field := range scope.Fields() {
 		if !field.IsBlank && !field.IsIgnored {
-			relationship := field.Relationship
-			if relationship != nil &&
+			if relationship := field.Relationship; relationship != nil &&
 				(relationship.Kind == "has_one" || relationship.Kind == "has_many" || relationship.Kind == "many_to_many") {
 				value := field.Field
 
@@ -57,70 +40,50 @@ func SaveAfterAssociations(scope *Scope) {
 					for i := 0; i < value.Len(); i++ {
 						newDB := scope.NewDB()
 						elem := value.Index(i).Addr().Interface()
+						newScope := newDB.NewScope(elem)
 
 						if relationship.JoinTable == "" && relationship.ForeignFieldName != "" {
-							newDB.NewScope(elem).SetColumn(relationship.ForeignFieldName, scope.PrimaryKeyValue())
+							newScope.SetColumn(relationship.ForeignFieldName, scope.PrimaryKeyValue())
 						}
+
 						if relationship.ForeignType != "" {
-							newDB.NewScope(elem).SetColumn(relationship.ForeignType, scope.TableName())
+							newScope.SetColumn(relationship.ForeignType, scope.TableName())
 						}
 
 						scope.Err(newDB.Save(elem).Error)
 
-						if relationship.JoinTable != "" {
-							if relationship.ForeignType != "" {
-								scope.Err(fmt.Errorf("gorm does not support polymorphic many-to-many associations"))
-							}
-
-							newScope := scope.New(elem)
-							joinTable := relationship.JoinTable
-							foreignKey := ToSnake(relationship.ForeignFieldName)
-							foreignValue := fmt.Sprintf("%v", scope.PrimaryKeyValue())
-							associationForeignKey := ToSnake(relationship.AssociationForeignFieldName)
-							associationForeignValue := fmt.Sprintf("%v", newScope.PrimaryKeyValue())
+						if joinTable := relationship.JoinTable; joinTable != "" {
+							quotedForeignDBName := scope.Quote(relationship.ForeignDBName)
+							foreignValue := scope.PrimaryKeyValue()
+							quoteAssociationForeignDBName := scope.Quote(relationship.AssociationForeignDBName)
+							associationForeignValue := newScope.PrimaryKeyValue()
 
 							newScope.Raw(fmt.Sprintf(
 								"INSERT INTO %v (%v) SELECT %v %v WHERE NOT EXISTS (SELECT * FROM %v WHERE %v = %v AND %v = %v);",
 								joinTable,
-								strings.Join([]string{scope.Quote(foreignKey), scope.Quote(associationForeignKey)}, ","),
+								strings.Join([]string{quotedForeignDBName, quoteAssociationForeignDBName}, ","),
 								strings.Join([]string{newScope.AddToVars(foreignValue), newScope.AddToVars(associationForeignValue)}, ","),
 								scope.Dialect().SelectFromDummyTable(),
 								joinTable,
-								scope.Quote(foreignKey),
+								quotedForeignDBName,
 								newScope.AddToVars(foreignValue),
-								scope.Quote(associationForeignKey),
+								quoteAssociationForeignDBName,
 								newScope.AddToVars(associationForeignValue),
 							))
 							scope.Err(scope.NewDB().Exec(newScope.Sql, newScope.SqlVars...).Error)
 						}
 					}
 				default:
-					newDB := scope.NewDB()
-					if value.CanAddr() {
-						if relationship.ForeignFieldName != "" {
-							newDB.NewScope(value.Addr().Interface()).SetColumn(relationship.ForeignFieldName, scope.PrimaryKeyValue())
-						}
-						if relationship.ForeignType != "" {
-							newDB.NewScope(value.Addr().Interface()).SetColumn(relationship.ForeignType, scope.TableName())
-						}
-						scope.Err(newDB.Save(value.Addr().Interface()).Error)
-					} else {
-						destValue := reflect.New(field.Field.Type()).Elem()
-
-						for _, f := range newDB.NewScope(field.Field.Addr().Interface()).Fields() {
-							destValue.FieldByName(f.Name).Set(f.Field)
-						}
-
-						elem := destValue.Addr().Interface()
-						if relationship.ForeignFieldName != "" {
-							newDB.NewScope(elem).SetColumn(relationship.ForeignFieldName, scope.PrimaryKeyValue())
-						}
-						if relationship.ForeignType != "" {
-							newDB.NewScope(value.Addr().Interface()).SetColumn(relationship.ForeignType, scope.TableName())
-						}
-						scope.Err(newDB.Save(elem).Error)
-						scope.SetColumn(field.Name, destValue.Interface())
+					elem := value.Addr().Interface()
+					newScope := scope.New(elem)
+					if relationship.ForeignFieldName != "" {
+						newScope.SetColumn(relationship.ForeignFieldName, scope.PrimaryKeyValue())
 					}
+
+					if relationship.ForeignType != "" {
+						newScope.SetColumn(relationship.ForeignType, scope.TableName())
+					}
+					scope.Err(scope.NewDB().Save(elem).Error)
 				}
 			}
 		}