On Dec 29, 2006, at 8:15 PM, Carl Karsten wrote:
> VFP's conflict detection dosen't happen until after the SQL UPDATE
> command is
> processed by the server. so I don't see how that is "ahead of time."
All it does is pad the WHERE clause with additional filters:
...WHERE pk = (pkVal)
AND updateField1 = oldval(updateField1)
AND updateField2 = oldval(updateField2)
AND updateField3 = oldval(updateField3)
AND updateField4 = oldval(updateField4)
...
If any of the fields have changed, nothing gets updated, since the
WHERE won't match. This is very different than issuing an update and
having the server actively reject it due to a modified state and/or
transactional lock.
> What backend would prevent an UPDATE command from updating that
> would update on some other server? we are talking standard SQL
> UPDATE command, right ?
There are transactional features and locking features that vary from
backend to backend. It isn't the UPDATE statement that's the issue.
-- Ed Leafe
-- http://leafe.com
-- http://dabodev.com
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