         if let table = db?[tableName]{
             let filter =  table.filter(self.id == objectId).limit(1)
             if filter.isEmpty{
-                table.insert(self.id <- objectId , self.json <- jsonString! , self.createTime <- NSDate())?
-            }else{
-                filter.update(self.json <- jsonString! , self.createTime <- NSDate() )?
+                table.insert(self.id <- objectId , self.json <- jsonString! , self.createdTime <- NSDate())?
+            }else{
+                filter.update(self.json <- jsonString! , self.createdTime <- NSDate() )?
             }
         }
        

        db?.create(table: db![tableName] , ifNotExists : true){t in
            t.column(self.id)
            t.column(self.json)
            t.column(self.createTime, defaultValue: NSDate())
            t.primaryKey(self.id)
        }
    }

    
    private let id = Expression<String>("id")
    private let json = Expression<String>("json")
    private let createdTime = Expression<NSDate>("createdTime")

    /**
    检查名字是否合法
