diff --git a/lectures/lecture4/code/beeblog/models/models.go b/lectures/lecture4/code/beeblog/models/models.go
index 2559ecf..c896dab 100644
--- a/lectures/lecture4/code/beeblog/models/models.go
+++ b/lectures/lecture4/code/beeblog/models/models.go
@@ -63,7 +63,11 @@ func RegisterDB() {
 func AddCategory(name string) error {
 	o := orm.NewOrm()
 
-	cate := &Category{Title: name}
+	cate := &Category{
+		Title:     name,
+		Created:   time.Now(),
+		TopicTime: time.Now(),
+	}
 
 	// 查询数据
 	qs := o.QueryTable("category")