Google Plus 21-digit URL Number Relationship to a Google Place's ID and Reference Numbers

问题

What is the relationship between a Google Place's ID and Reference Number and the same Place's 21-digit Google Plus number used in the Place's Google Plus URL?

I want to link Google Plus URLs for 100's of different businesses to my website. However, I do not know the Google Plus URL address for each of the businesses. But I do know the Google Place ID and Reference Number for each of the businesses. Can I derive the 21-digit Google Plus Number for a business from their Google Places ID and Reference Number? If I can, what is the formula that creates the 21-digit Google Plus Number?

Or is the Google Plus number completely random so that there is no relationship at all with the Google Place's ID and Reference Number?

回答1:

The ID gives you the URL, just prefix it with "https://plus.google.com/" but as far as I know there is no way to get a ref from the ID. The ref is returned by an API search and when you have a valid ref if you want to ask detail ( i.e reviews ) from this ref you must keep it somewhere and it's a pain because it's a very long string. So if somebody knows how to get the ref from a ID that would be great !

回答2:

Google's 21-digit number is a numeric form of your UserID.

Most Google sites & API's that identify the UserID in the URL will function properly while interchangeably using any of:

• your "text" UserID (your Gmail address to the left of the @),

• your 21-digit numeric UserID (as determined below), or,

• the word default in place of either (representing the currently authenticated user).

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One way to see your numeric UserID is to — while logged into your Google Account — go to:

   https://picasaweb.google.com/data/feed/api/user/default/

The 21-digit page title is your numeric Google UserID.

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If you have a 21-digit number that you want to confirm is yours, go to:

   https://plus.google.com/ _21digitUserID_

If it loads your Plus page, that's your numeric Google UserID. _{(Unless you, like me, have deactivated your Google Plus page!)}

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"Kinda Related" Bonus Tip:
You can insert + plus signs followed by text after your Gmail address — and add/remove . dots anywhere in your Gmail address — without a problem.

So, these would all get delivered to the same place:

abc123@gmail.com       abc123+SortToMySecretFolder@gmail.com       a.b.c.123@gmail.com
abc123+camping.trip@gmail.com    abc.123@gmail.com   abc123+spam.site.signup@gmail.com

You could utilize this by creating rules to handle each address in a different way, or even track which websites are selling your email address to spammers. _(Source)

来源：https://stackoverflow.com/questions/16753404/google-plus-21-digit-url-number-relationship-to-a-google-places-id-and-referenc