The `UserInfo` table in Microsoft Access when linked to a SharePoint list is a hidden system table that Access automatically creates to manage user information related to the SharePoint list. It's not part of the SharePoint list itself, but rather a local Access table used for resolving user IDs to user names and other user details.
Here's a breakdown of why and how it appears:
* **User ID Resolution:** SharePoint stores user information primarily using user IDs (numeric identifiers). However, Access displays user names in its interface. The `UserInfo` table acts as a lookup table to translate those numeric IDs from SharePoint into the corresponding display names, email addresses, and other user properties that are easier for users to understand.
* **Caching User Data:** Access caches the user information in the `UserInfo` table to avoid repeatedly querying SharePoint for the same user details. This improves performance, especially when working with lists that have many users or user-related fields (like "Created By," "Modified By," or custom people fields).
* **Automatic Creation and Maintenance:** Access automatically creates the `UserInfo` table when you link to a SharePoint list that contains user-related columns. It also attempts to keep the table synchronized with the user information on the SharePoint server. However, synchronization isn't always perfect or immediate.
* **Hidden Status:** By default, the `UserInfo` table is hidden in the Access navigation pane. You typically won't see it unless you change your Access options to show system objects. To view hidden objects:
1. Go to **File > Options**.
2. Click **Current Database**.
3. In the "Navigation" section, check the box labeled "Show System Objects."
4. Click **OK**. You might need to close and reopen the database for the change to take effect.
* **Table Structure:** The `UserInfo` table typically contains fields such as:
* `ID`: The user ID from SharePoint.
* `EMail`: The user's email address.
* `Name`: The user's display name.
* `Notes`: (Sometimes used for additional user information).
* Other fields may be present depending on the user profile information available in SharePoint.
**Important Considerations:**
* **Read-Only:** The `UserInfo` table is generally read-only. You should *not* directly modify data in this table, as any changes you make will likely be overwritten when Access synchronizes with SharePoint.
* **Synchronization Issues:** Sometimes, the `UserInfo` table might not be perfectly synchronized with the SharePoint user directory. This can lead to issues where user names appear incorrectly or are not resolved. If you suspect synchronization problems, you can try refreshing the linked table or relinking the table. Closing and reopening the database can also sometimes help.
* **Permissions:** The information in the `UserInfo` table is based on the user's permissions in SharePoint. If a user doesn't have permission to access certain user profile information, it might not be available in the `UserInfo` table.
* **SharePoint Version:** The exact behavior and structure of the `UserInfo` table can vary slightly depending on the version of SharePoint you are connecting to.
In summary, the `UserInfo` table is an essential component that enables Access to display user-friendly names and information when working with SharePoint lists, by translating SharePoint's internal user IDs into human-readable details.
