add invite system

app/db.py

@@ -201,6 +201,19 @@ class Model:
         return instance
 
 
+    @classmethod
+    def findall(cls, condition):
+        rows = db.QueryBuilder(cls.table)\
+            .where(condition)\
+            .all()
+        res = []
+        for row in rows:
+            instance = cls(cls.table)
+            instance._data = dict(row)
+            res.append(instance)
+        return res
+
+
     @classmethod
     def create(cls, values):
         if not values: