diff --git a/dao/msg.go b/dao/msg.go
index 40424ba..afb0cf2 100644
--- a/dao/msg.go
+++ b/dao/msg.go
@@ -8,7 +8,7 @@ import (
 type AIStreamMsg struct {
 	gorm.Model
 	Type      string `gorm:"column:type"`
-	ModelID   uint   `gorm:"column:model_id"`
+	ModelID   uint   `gorm:"column:model_id index:idx_covering,unique"`
 	UserID    int    `gorm:"column:user_id"`    //用户id
 	SessionID int    `gorm:"column:session_id"` //会话id
 	MSG       string `gorm:"column:msg"`        //消息内容