diff --git a/app/src/main/java/com/gh/gamecenter/room/AppDatabase.java b/app/src/main/java/com/gh/gamecenter/room/AppDatabase.java
index 7f9402ff9b..4b716a4008 100644
--- a/app/src/main/java/com/gh/gamecenter/room/AppDatabase.java
+++ b/app/src/main/java/com/gh/gamecenter/room/AppDatabase.java
@@ -8,10 +8,10 @@ import android.arch.persistence.room.migration.Migration;
 import android.content.Context;
 import android.support.annotation.NonNull;
 
-import com.gh.gamecenter.qa.entity.AnswerEntity;
 import com.gh.gamecenter.entity.LoginTokenEntity;
 import com.gh.gamecenter.entity.SignEntity;
 import com.gh.gamecenter.entity.UserInfoEntity;
+import com.gh.gamecenter.qa.entity.AnswerEntity;
 import com.gh.gamecenter.room.dao.AnswerDao;
 import com.gh.gamecenter.room.dao.SignDao;
 import com.gh.gamecenter.user.LoginTokenDao;
@@ -77,7 +77,7 @@ public abstract class AppDatabase extends RoomDatabase {
         @Override
         public void migrate(@NonNull SupportSQLiteDatabase database) {
             database.execSQL("Alter TABLE AnswerEntity add articleTitle TEXT");
-            database.execSQL("Alter TABLE AnswerEntity add type TEXT NOT NULL");
+            database.execSQL("Alter TABLE AnswerEntity add type TEXT NOT NULL DEFAULT ''");
         }
     };