ER 图：Table 未连接到任何其他 table
ER Diagram: Table that is not connected to any other table
我正在看几年前放在一起的 ER 图。图中有一个 table 未连接到任何其他 table。
这个 table 有什么用途/它可以用来做什么？
我尝试搜索 Whosebug 和 Google，但实际上没有人回答这个问题。
编辑 #1：澄清
我的印象是所有 table 都必须在 ER 图中以某种方式连接，如果不是，则有问题。
我和比我年长的人谈过，他们是这样向我解释的：
Let's pretend I am building an ER diagram for a restaurant.
I have 3 tables:
- Orders
- Employees
- Inventory
These are all in the same ER diagram. Tables 1 and 2 are connected,
but nothing is connected to table 3.
Tables do not all have to be connected in an ER Diagram, but there has
to be a purpose for having it there.
If we are creating an ERD to show seating availability, having table 3
would not make any sense as it is not relevant.
If we are designing the whole restaurant set of processes, then you
can have stuff that isn't connected as they will obviously be part of
their own contained processes.
TLDR:并非所有表都必须在 ER 图中连接，但所有
表格应与同一组流程相关。
我正在看几年前放在一起的 ER 图。图中有一个 table 未连接到任何其他 table。
这个 table 有什么用途/它可以用来做什么？
我尝试搜索 Whosebug 和 Google，但实际上没有人回答这个问题。
编辑 #1：澄清
我的印象是所有 table 都必须在 ER 图中以某种方式连接，如果不是，则有问题。
我和比我年长的人谈过，他们是这样向我解释的：
Let's pretend I am building an ER diagram for a restaurant.
I have 3 tables:
- Orders
- Employees
- Inventory
These are all in the same ER diagram. Tables 1 and 2 are connected, but nothing is connected to table 3.
Tables do not all have to be connected in an ER Diagram, but there has to be a purpose for having it there.
If we are creating an ERD to show seating availability, having table 3 would not make any sense as it is not relevant.
If we are designing the whole restaurant set of processes, then you can have stuff that isn't connected as they will obviously be part of their own contained processes.
TLDR:并非所有表都必须在 ER 图中连接，但所有 表格应与同一组流程相关。