SQL UPDATE TOP with ORDER BY?

Question

I have a following query:

UPDATE TOP (@MaxRecords) Messages 
SET    status = \'P\' 
OUTPUT inserted.* 
FROM   Messages 
where Status = \'N\'
and InsertDate &         


        

Answer 1

the correct syntax of update is

UPDATE [LOW_PRIORITY] [IGNORE] table_reference
SET col_name1={expr1|DEFAULT} [, col_name2={expr2|DEFAULT}] ...
[WHERE where_condition]
[ORDER BY ...]
[LIMIT row_count]

Answer 2

You can try sub query like

  UPDATE Messages 
    SET    status = 'P' 
    WHERE MessageId IN (SELECT TOP (@MaxRecords) MessageId FROM Messages where Status = 'N' and InsertDate >= GETDATE() ORDER BY Priority)
output inserted.*

Answer 3

you can use common table expression for this:

;with cte as (
   select top (@MaxRecords)
       status
   from Messages 
   where Status = 'N' and InsertDate >= getdate()
   order by ...
)
update cte set
    status = 'P'
output inserted.*

This one uses the fact that in SQL Server it's possible to update cte, like updatable view.