schema: Continue

Signed-off-by: Jan Lindemann <jan@janware.com>

tools/python/jwutils/db/schema/SingleForeignKey.py

@@ -1,19 +1,33 @@
 # -*- coding: utf-8 -*-
 
-from typing import Optional, List, Any
+from typing import Optional, Any
 
+from .Column import Column
 from .ColumnSet import ColumnSet
 
 class SingleForeignKey:
 
-    def __init__(self, child_col, parent_col):
+    def __init__(self, child_col: Column, parent_col: Column):
         self.__child_col = child_col
         self.__parent_col = parent_col
+        self.__iterable = (self.__child_col, self.__parent_col)
+
+    def __len__(self):
+        return 2
+
+    def __iter__(self):
+        yield from self.__iterable
+
+    def __repr__(self):
+        return f'{self.__child_col.table.name}.{self.__child_col.name} -> {self.__parent_col.table.name}.{self.__parent_col.name}'
+
+    def __getitem__(self, index):
+        return self.__iterable[index]
 
     @property
-    def child_col(self):
+    def child_column(self):
         return self.__child_col
 
     @property
-    def parent_col(self):
+    def parent_column(self):
         return self.__parent_col