Ideally I want to do this:
UPDATE TOP (10) messages SET status=10 WHERE status=0 ORDER BY priority DESC;
In English: I want to get the top 10 available (status=0) messages from the DB and lock them (status=10). A message with a higher priority should be gotten first.
unfortunately MS SQL doesn't allow an order by clause in the update.
Anyway how to circumvent this?
You can do a subquery where you first get the IDs of the top 10 ordered by priority and then update the ones that are on that sub query:
UPDATE messages
SET status=10
WHERE ID in (SELECT TOP (10) Id
FROM Table
WHERE status=0
ORDER BY priority DESC);