Help with combining two queries

I have a stored procedure that needs to retrieve the top 1000 sent items and
the top 1000 received items - each ordered by date. So, effectively, the
most recent 1000 sent items and the most recent 1000 received items. Then, I
need to combine them into one result set and again take the top 1000 items
when ordered by date.
Originally, the stored procedure created a temp table and inserted the
results of each query consecutively, then did a SELECT TOP to get the final
results. Because of high traffic, this is killing the DB server. I suspect
that the queries could be combined into one query. I also tried a UNION of
the two selects, but that doesn't work because I need to do have accurate
results on the subquery first (top 1000 ordered by date). Can anyone help me
determine a more effecient solution, preferrably to combine the two queries
into one? I have slimmed down the two queries significantly to show only the
differences. They are below.
DECLARE @.userName AS VARCHAR(25)
SELECT @.userName = 'MyUserName'
-- Gets the sent items
--
SELECT TOP 1000
@.userName as SenderName,
'Sent' AS SentReceived,
u.[user_name] as ReceiverName
FROM dbo.Email_Type (nolock)
INNER JOIN dbo.Email (nolock) ON dbo.Email_Type.ID = dbo.Email.Type
INNER JOIN dbo.Email_Folders (nolock) ON dbo.Email.Folder =
dbo.Email_Folders.ID
RIGHT OUTER JOIN [Profile].dbo.Contact_history ch (nolock) ON dbo.Email.ID =
ch.source_id_guid
INNER JOIN [Profile].dbo.user_profile u (nolock) ON ch.[contact_user_id] =
u.[user_id]
WHERE
ch.[user_id] = @.UserID
ORDER BY
ch.createstamp DESC
-- Gets the received items
--
SELECT TOP 1000
u.[user_name] as SenderName,
'Received' AS SentReceived,
@.userName as ReceiverName
FROM dbo.Email_Type (nolock)
INNER JOIN dbo.Email (nolock) ON dbo.Email_Type.ID = dbo.Email.Type
INNER JOIN dbo.Email_Folders (nolock) ON dbo.Email.Folder =
dbo.Email_Folders.ID
RIGHT OUTER JOIN [Profile].dbo.Contact_history ch (nolock) ON dbo.Email.ID =
ch.source_id_guid
INNER JOIN [Profile].dbo.user_profile u (nolock) ON ch.[user_id] =
u.[user_id]
WHERE
ch.[contact_user_id] = @.UserID
ORDER BY
ch.createstamp DESCHello, karch
You probably want a query like this:
SELECT TOP 1000 *
FROM (
SELECT TOP 1000 <your columns>
FROM <sent items>
ORDER BY TheDate
UNION ALL
SELECT TOP 1000 <your columns>
FROM <sent items>
ORDER BY TheDate
) x
ORDER BY TheDate
However, I think the above query will give the same results as this
query (as long as TheDate is unique among all rows):
SELECT TOP 1000 *
FROM (
SELECT <your columns>
FROM <sent items>
UNION ALL
SELECT <your columns>
FROM <sent items>
) x
ORDER BY TheDate
Razvan|||Yes, but I dont think you can have ORDER BY in the subqueries if you UNION -
I tried this approach and received an error. But, yes, logically that is
what I want to accomplish.
"Razvan Socol" <rsocol@.gmail.com> wrote in message
news:1146597584.838889.18770@.v46g2000cwv.googlegroups.com...
> Hello, karch
> You probably want a query like this:
> SELECT TOP 1000 *
> FROM (
> SELECT TOP 1000 <your columns>
> FROM <sent items>
> ORDER BY TheDate
> UNION ALL
> SELECT TOP 1000 <your columns>
> FROM <sent items>
> ORDER BY TheDate
> ) x
> ORDER BY TheDate
> However, I think the above query will give the same results as this
> query (as long as TheDate is unique among all rows):
> SELECT TOP 1000 *
> FROM (
> SELECT <your columns>
> FROM <sent items>
> UNION ALL
> SELECT <your columns>
> FROM <sent items>
> ) x
> ORDER BY TheDate
> Razvan
>|||In this case, try another level of subqueries:
SELECT TOP 1000 *
FROM (
SELECT * FROM (
SELECT TOP 1000 <your columns>
FROM <sent items>
ORDER BY TheDate
) a
UNION ALL
SELECT * FROM (
SELECT TOP 1000 <your columns>
FROM <sent items>
ORDER BY TheDate
) b
) x
ORDER BY TheDate
Razvan