diff --git a/api/graphql.go b/api/graphql.go
index 94b3610..de2ee51 100644
--- a/api/graphql.go
+++ b/api/graphql.go
@@ -106,6 +106,9 @@ func NewSchema() (graphql.Schema, error) {
 							for _, field := range fieldAST.SelectionSet.Selections {
 								fieldAST, ok := field.(*ast.Field)
 								if ok {
+									//if fieldAST.Name.Value == "avatar" {
+									//	fieldAST.Name.Value = fmt.Sprintf("IFNULL(%s,'')", fieldAST.Name.Value)
+									//}
 									fields = append(fields, fieldAST.Name.Value)
 								}
 							}
diff --git a/api/struct.go b/api/struct.go
index b70fabe..6aa3384 100644
--- a/api/struct.go
+++ b/api/struct.go
@@ -27,9 +27,9 @@ type Image struct {
 
 type User struct {
 	ID         int       `json:"id"          db:"id"`
-	UserName   string    `json:"user_name"   db:"user_name"`
-	Avatar     string    `json:"avatar"      db:"avatar"`
-	Rank       string    `json:"rank"        db:"rank"`
+	UserName   *string   `json:"user_name"   db:"user_name"`
+	Avatar     *string   `json:"avatar"      db:"avatar"`
+	Rank       *string   `json:"rank"        db:"rank"`
 	CreateTime time.Time `json:"create_time" db:"create_time"`
 	UpdateTime time.Time `json:"update_time" db:"update_time"`
 }