add DB level propagation for the Unscoped flag

gorm.go

@@ -50,6 +50,8 @@ type Config struct {
 	CreateBatchSize int
 	// TranslateError enabling error translation
 	TranslateError bool
+	// PropagateUnscoped propagate Unscoped to every other nested statement
+	PropagateUnscoped bool
 
 	// ClauseBuilders clause builder
 	ClauseBuilders map[string]clause.ClauseBuilder
@@ -409,6 +411,9 @@ func (db *DB) getInstance() *DB {
 				Vars:      make([]interface{}, 0, 8),
 				SkipHooks: db.Statement.SkipHooks,
 			}
+			if db.Config.PropagateUnscoped {
+				tx.Statement.Unscoped = db.Statement.Unscoped
+			}
 		} else {
 			// with clone statement
 			tx.Statement = db.Statement.clone()

tests/hooks_test.go

@@ -566,3 +566,41 @@ func TestUpdateCallbacks(t *testing.T) {
 		t.Fatalf("before update should not be called")
 	}
 }
+
+type Product6 struct {
+	gorm.Model
+	Name string
+	Item *ProductItem2
+}
+
+type ProductItem2 struct {
+	gorm.Model
+	Product6ID uint
+}
+
+func (p *Product6) BeforeDelete(tx *gorm.DB) error {
+	if err := tx.Delete(&p.Item).Error; err != nil {
+		return err
+	}
+	return nil
+}
+
+func TestPropagateUnscoped(t *testing.T) {
+	DB.Migrator().DropTable(&Product6{}, &ProductItem2{})
+	DB.AutoMigrate(&Product6{}, &ProductItem2{})
+
+	p := Product6{
+		Name: "unique_code",
+		Item: &ProductItem2{},
+	}
+	DB.Model(&Product6{}).Create(&p)
+
+	DB.PropagateUnscoped = true
+	defer func() {
+		DB.PropagateUnscoped = false
+	}()
+
+	if err := DB.Unscoped().Delete(&p).Error; err != nil {
+		t.Fatalf("unscoped did not propagate")
+	}
+}