When do conflicts occur?
A conflict arises when two users make a change to the same portion of a list's data or structure. The user who submits a change first will succeed in committing his or her changes, but the second user will be notified of a conflict.
Types of changes that you can make to a list
You can make three types of changes to a list. The following table lists each type along with some examples:
| Type of change | Examples |
|---|---|
| Change a list's data | Add, modify, or delete a row Paste Clipboard contents Add data to cells by dragging the fill handle Add or delete attachments Format the contents of one or more cells |
| Modify the structure of a list | Add or delete a column Change the settings of a column Make changes to a calculated column Change list settings |
| Change the view definition |
Apply a filter or a sort order Change column width or row height Change column order Show or hide the Total row |
Scenarios that will result in a conflict
The following table summarizes the scenarios in which a conflict will arise:
| User A | User B |
|---|---|
| Deletes a row | Updates the same row |
| Updates a row | Updates or deletes the same row Note In a document library, if user A updates a row or a document, and user B deletes the same row or document, a conflict will not arise. |
| Adds or deletes an attachment using the browser | Updates or deletes the same row |
| Deletes a document | Updates the same row |
| Edits, renames, or saves a document | Updates the same row |
| Updates a row without editing document | Updates the same row |
| Changes rich text formatting | Updates or deletes the same row |
In a document library, if user A opens a document and user B edits the document or changes its settings, user B will receive an error indicating that the document is locked.
Scenarios that will not result in a conflict
The following table summarizes the scenarios in which a conflict will not arise:
| User A | User B | Example |
|---|---|---|
| Changes data | Changes view definition | User A adds a row and user B applies a sort order to the view |
| Changes structure | Changes view definition | User A adds a column, and user B applies a sort order to the view |
| Changes view definition | Changes data | User A applies a sort order, and user B adds a row |
| Changes view definition | Changes structure | User A applies a sort order, and user B adds a column |
| Changes view definition | Changes view definition | User A applies a sort order, followed by user B applying a different sort order
Note Because the last change persists, user B's change will overwrite user A's change |
Note In a document library, if users A and B open a document in read-only mode, and subsequently decide to edit and save the document by replacing the existing version, the user who saves second will overwrite the changes made by the other user.
Scenarios that will result in a structural conflict
The following table summarizes the scenarios in which an error message will be displayed. User B will be prompted to refresh the list, and their changes will be discarded.
| User A | User B |
|---|---|
| Deletes a column | Updates data in the same column |
| Changes the data type of a column | Adds or updates data with type mismatch |
| Adds, renames, or deletes a column, changes a column's data type or other properties | Edits a calculated column |
| Makes list-level changes, such as renames the list, changes its description or security settings, rearranges the columns, enables or disables attachments, or adds the list to the Quick Launch bar | Edits a calculated column |
| Edits a calculated column | Adds, renames, or deletes a column, changes a column's data type or other properties. Note User B must be on the Add Column or Change Column page before user A starts editing the calculated column |
| Edits a calculated column | Makes list-level changes, such as renames the list, changes its description or security settings, rearranges the columns, enables or disables attachments, or adds the list to the Quick Launch bar Note User B must be on the List Settings page before user A starts editing the calculated column. |
Scenarios that will not result in an error message or conflict
The following table summarizes the scenarios in which neither an error nor a conflict will occur:
| User A | User B |
|---|---|
| Deletes a column | Deletes the same column |
| Deletes an attachment | Deletes the same attachment |
| Deletes a document | Deletes the same document or row |
| Deletes a row | Deletes the same row |