diff --git a/douzero/server/orm.py b/douzero/server/orm.py
index 9e66c45..69bef65 100644
--- a/douzero/server/orm.py
+++ b/douzero/server/orm.py
@@ -15,9 +15,9 @@ class BaseModel(Model):
     database = db
 
 class Model(BaseModel):
-  path = CharField(primary_key=True)
-  position = CharField(null = False)
-  type = CharField(null = False)
+  path = CharField(primary_key=True, max_length=255)
+  position = CharField(null = False, max_length=32)
+  type = CharField(null = False, max_length=32)
   frame = IntegerField(null = False)
   create_time = DateTimeField(null=False)
   class Meta:
@@ -26,8 +26,8 @@ class Model(BaseModel):
 
 class Battle(BaseModel):
   id = PrimaryKeyField()
-  challenger_path = CharField(null = False, index = True)
-  challenger_position = CharField(null = False)
+  challenger_path = CharField(null = False, max_length=255, index = True)
+  challenger_position = CharField(null = False, max_length=32)
   opponent_rank = IntegerField(null = False)
   status = IntegerField(null = False, index = True)
   challenger_wp = DecimalField(null=True)