SQL联合按内部查询然后按整个联合选择顺序

Question

I have created a SQL UNION string that looks like this and works (the {dData} and similar placeholders are filled in by VB.Net code):

SELECT LEFT({dData}.PLATE,7) AS Plates, 
    {dData}.SIGHTING_DT AS LPRReadDate, 
    {dLov}.LOCATION AS LPRLocation 
FROM {dData} 
INNER JOIN {dLov} ON ({dData}.ROAD_NAME = {dLov}.ROAD_NAME) AND ({dData}.READER = {dLov}.READER) 
WHERE ({dData}.SIGHTING_DT >= @sdate AND {dData}.SIGHTING_DT <= @edate) 
    AND (LEN(COALESCE({dData}.PLATE,'')) = @slen1 OR LEN(COALESCE({dData}.PLATE,'')) = @slen2) 
    AND {dData}.PLATE NOT LIKE @rx1 
    AND {dData}.PLATE = @pf 
UNION 
SELECT LEFT({vData}.PLATE,7) AS Plates, 
    {vData}.SIGHTING_DT AS LPRReadDate, 
    {vLov}.LOCATION AS LPRLocation 
FROM {vData} 
INNER JOIN {vLov} ON {vData}.CAMERA = {vLov}.CAMERA 
WHERE ({vData}.SIGHTING_DT >= @sdate AND {vData}.SIGHTING_DT <= @edate) 
    AND (LEN(COALESCE({vData}.PLATE,'')) = @slen1 OR LEN(COALESCE({vData}.PLATE,'')) = @slen2) 
    AND {vData}.PLATE NOT LIKE @rx1 
    AND {vData}.PLATE = @pf 
ORDER BY LPRReadDate

The problem is I need to get the Top 1 and Order the second Select statement by LPRRead Date in Descending Order. I tried doing it like this.

SELECT LEFT({dData}.PLATE,7) AS Plates, 
    {dData}.SIGHTING_DT AS LPRReadDate, 
    {dLov}.LOCATION AS LPRLocation 
FROM {dData} 
INNER JOIN {dLov} ON ({dData}.ROAD_NAME = {dLov}.ROAD_NAME) AND ({dData}.READER = {dLov}.READER) 
WHERE ({dData}.SIGHTING_DT >= @sdate AND {dData}.SIGHTING_DT <= @edate) 
    AND (LEN(COALESCE({dData}.PLATE,'')) = @slen1 OR LEN(COALESCE({dData}.PLATE,'')) = @slen2) 
    AND {dData}.PLATE NOT LIKE @rx1 
    AND {dData}.PLATE = @pf 
UNION 
(SELECT TOP 1 LEFT({vData}.PLATE,7) AS Plates, 
    {vData}.SIGHTING_DT AS LPRReadDate, 
    {vLov}.LOCATION AS LPRLocation 
FROM {vData} 
INNER JOIN {vLov} ON {vData}.CAMERA = {vLov}.CAMERA 
WHERE ({vData}.SIGHTING_DT >= @sdate AND {vData}.SIGHTING_DT <= @edate) 
    AND (LEN(COALESCE({vData}.PLATE,'')) = @slen1 OR LEN(COALESCE({vData}.PLATE,'')) = @slen2) 
    AND {vData}.PLATE NOT LIKE @rx1 
    AND {vData}.PLATE = @pf 
ORDER BY {vLov}.CREATED_DT DESC)  
ORDER BY LPRReadDate

But, I am getting this error:

Syntax Error near 'ORDER'.

I am sure that I need to do some kind of sub-query. I've tried to figure it out by looking at examples online, but I can't figure it out.

Update @UnhandledExcepSean I tried adapting what you said to my code. After a couple more syntax errors, I arrived at the code below. But whenever I try to run it, it just times out the server. Can you tell me if it looks correct or if there are any changes that might need to be made....

SELECT 
  Plates, LPRReadDate, LPRLocation 
FROM(
    SELECT TOP 1 
        LEFT({vData}.PLATE,7) AS Plates, {vData}.SIGHTING_DT AS LPRReadDate, {vLov}.LOCATION AS LPRLocation 
    FROM {vData} 
    INNER JOIN {vLov} ON {vData}.CAMERA = {vLov}.CAMERA 
    WHERE ({vData}.SIGHTING_DT >= @sdate AND {vData}.SIGHTING_DT <= @edate) 
        AND (LEN(COALESCE({vData}.PLATE,'')) = @slen1 OR LEN(COALESCE({vData}.PLATE,'')) = @slen2) 
        AND {vData}.PLATE NOT LIKE @rx1 
        AND {vData}.PLATE = @pf 
    ORDER BY {vLov}.CREATED_DT DESC
    ) test 
UNION
SELECT LEFT({EOCdata}.PLATE,7) AS Plates, 
    {EOCdata}.SIGHTING_DT AS LPRReadDate, 
    {EOClov}.LOCATION AS LPRLocation 
FROM {EOCdata} 
INNER JOIN {EOClov} ON ({EOCdata}.CAMERA = {EOClov}.CAMERA) AND ({EOCdata}.READER = {EOClov}.READER) 
WHERE ({EOCdata}.SIGHTING_DT >= @sdate AND {EOCdata}.SIGHTING_DT <= @edate) 
    AND (LEN(COALESCE({EOCdata}.PLATE,'')) = @slen1 OR LEN(COALESCE({EOCdata}.PLATE,'')) = @slen2) 
    AND {EOCdata}.PLATE NOT LIKE @rx1 
    AND {EOCdata}.PLATE = @pf 
ORDER BY LPRReadDate

Answer 1

You can work around the issue thusly:

DECLARE @t TABLE ( Field1 INT,Field2 INT)
INSERT INTO @t (Field1,Field2) SELECT 1,1
INSERT INTO @t (Field1,Field2) SELECT 2,2
INSERT INTO @t (Field1,Field2) SELECT 3,3

SELECT
    Field1,Field2
FROM(
    SELECT TOP 1
        Field1,Field2
    FROM @t
    ORDER BY Field1 ASC
) test
UNION
SELECT
    Field1,Field2
FROM @t
ORDER BY Field2 DESC

Answer 2

Thanks for the help everyone. I was finally able to work out how to do it. In case anyone might find it useful, I'll post what I came up with below. The derivedTable portion is that part that I was trying to figure out.

        WITH derivedTable 
        AS 
        (
            SELECT {vLov}.LPR_VIGILANT_LOV_ID, 
            {vLov}.CAMERA, 
            {vLov}.LOCATION, 
            {vLov}.CREATED_DT, 
            ROW_NUMBER() OVER (Partition By {vLov}.CAMERA 
                                ORDER BY {vLov}.CREATED_DT DESC) rn 
            FROM {vLov}
        ) 
        SELECT LEFT({vData}.PLATE,7) AS Plates, 
        {vData}.SIGHTING_DT AS LPRReadDate,          
        derivedTable.LOCATION 
        FROM {vData} 
        INNER JOIN derivedTable ON {vData}.CAMERA = derivedTable.CAMERA 
        WHERE ({vData}.SIGHTING_DT >= @sdate AND {vData}.SIGHTING_DT <= @edate) 
        AND (LEN(COALESCE({vData}.PLATE,'')) = @slen1 OR LEN(COALESCE({vData}.PLATE,'')) = @slen2) 
        AND {vData}.PLATE NOT LIKE @rx1 
        AND {vData}.LOCATION = @lf 
        AND derivedTable.rn = 1 
        UNION 
        SELECT LEFT({EOCdata}.PLATE,7) AS Plates, 
            {EOCdata}.SIGHTING_DT AS LPRReadDate, 
            {EOClov}.LOCATION AS LPRLocation 
        FROM {EOCdata} 
        INNER JOIN {EOClov} ON ({EOCdata}.CAMERA = {EOClov}.CAMERA) AND ({EOCdata}.READER = {EOClov}.READER) 
        WHERE ({EOCdata}.SIGHTING_DT >= @sdate AND {EOCdata}.SIGHTING_DT <= @edate) 
        AND (LEN(COALESCE({EOCdata}.PLATE,'')) = @slen1 OR LEN(COALESCE({EOCdata}.PLATE,'')) = @slen2) 
        AND {EOCdata}.PLATE NOT LIKE @rx1 
        AND {EOCdata}.LOCATION = @lf