Sql 如何在表中动态添加列？

我想添加两个表。但是，我应该如何区分哪些条目来自哪个表呢

表1 表2 结果应该是：

col1 tablename
----------------
a     table1
b      "
c      "
d     table2
e      "
f      "

---

Alis，你没有接受我们之前的答案！解释你自己！

1
2
3

col1 tablename
----------------
a     table1
b      "
c      "
d     table2
e      "
f      "

Select Table1.Col1, "Table1" as 'TableName'
From dbo.Table1

Union all

Select Table2.Col1, "Table2" as 'TableName'
From dbo.Table2