问题
A user can turn on or off notification settings for his account, for notifications such as Changed Account Profile Information, Received New Message etc
Notification can be sent via email or mobile phone (either push or sms), user can have 1 email only and many mobile phone devices.
Is there any way you would improve the following database design or would you do it differently?
let me know thanks
USER_NOTIFICATION_SETTING
Id
UserId
Notification_SettingCode
NotificationTypeCode
UserDeviceId -- the mobile deviceid
IsEnabled -- true (notification is on), false (notification is off)
NOTIFICATION_SETTING
Code - e.g 1001, 1002
Name -- e.g Changed Account Profile Information, Received New Message etc
NOTIFICATION_TYPE
Code - e.g 1001, 1002
Name -- e.g Email, SMS, Push
USER_DEVICE -- the mobile phone device information
etc...etc...
回答1:
Or maybe this one which propagates natural keys. This has wider tables, but requires less joins. For example, you can get notifications for a UserName directly from the NotificationQueue.
Or this one, which is good enough if you have phone and email only. So far the simplest -- I think that currently I like this one the best.
回答2:
What you've done looks pretty good actually. I would out of personal preference do the following:
- Eliminate the UserId column on User_Notification_Setting as it should already be on your User_Device table
- Get rid of the _s in your table names
- Change the Code fields in Notification_Setting and Notification_Type to be Id (even if they are not Identity columns) and then change the foreign key references from other tables to have a more consistent NotificationTypeId field name.
- Eliminate the IsEnabled field. The fact that a record exists at the intersection should suffice for having the notification. Deletion of that record means that there is no notification. I can see why you might want to remember that a notification was there at one time and maybe have it there to easily re-enable but I see no information stored at the intersection so deletion is just as good.
回答3:
Looks good, only a few minor suggestions:
- Naming of code fields, use table name then _Code
- Add a notification for all changes
There are a couple of things I do not agree with Tahbaza on:
- I would leave the user id in, it is then faster to get all notifications for a user
- I would leave the isEnabled in, it is then possible to temporarily stop all notifications
来源：https://stackoverflow.com/questions/4774051/database-design-for-notification-settings