Editing Record issues in Access / SQL (Write Conflict)
a problem has come up after a SQL DB I used was migrated to a new server. Now when trying to edit a record in Access (form or table), it says: WRITE CONFLICT: This record has been changed by another user since you started editing it...
Are there any non obvious reasons for this. There is noone else using the server, I've disabled any triggers on the Table. I've just found that it is something to do with NULLs as records that have none are ok, but some rows which have NULLs are not. Could it be to do with indexes? If it is relevant, I have recently started BULK uploading daily, rather than doing it one at a time using INSERT INTO from Access.
Answer
Possible problems:
1 Concurrent edits
A reason might be that the record in question has been opened in a form that you are editing. If you change the record programmatically during your editing session and then try to close the form (and thus try to save the record), access says that the record has been changed by someone else.
Save the form before changing the record programmatically.
In the form:
'This saves the form's current record
Me.Dirty = False
'Now, make changes to the record programmatically
2 Missing primary key or timestamp
Make sure the SQL-Server table has a primary key as well as a timestamp column.
The timestamp column helps Access to determine if the record has been edited since it was last selected. Access does this by inspecting all fields, if no timestamp is available. Maybe this does not work well with null entries if there is no timestamp column (see 3 Null bits issue).
The timestamp actually stores a row version number and not a time.
Don't forget to refresh the table link in access after adding a timestamp column, otherwise Access won't see it. (Note: Microsoft's Upsizing Wizard creates timestamp columns when converting Access tables to SQL-Server tables.)
3 Null bits issue
According to @AlbertD.Kallal this could be a null bits issue described here: KB280730. If you are using bit fields, set their default value to 0 and replace any NULLs entered before by 0. I usually use a BIT DEFAULT 0 NOT NULL for Boolean fields as it most closely matches the idea of a Boolean.
The KB article says to use an *.adp instead of a *.mdb; however, Microsoft discontinued the support for Access Data Projects (ADP) in Access 2013.