Question

我创建了一个看起来像这样且工作的SQL UNION字符串（{dData}和类似的占位符由VB.Net代码填充）：

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

问题是我需要按降序排列LPRRead日期获得前1名和订购第二个Select语句。我试着这样做。

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

但是，我收到了这个错误：

＆＃39; ORDER＆＃39;附近的语法错误。

我确信我需要做一些子查询。我试图通过在线查看示例来解决这个问题，但我无法弄明白。

更新 @UnhandledExcepSean我尝试调整你所说的代码。经过几次语法错误后，我得到了下面的代码。但每当我尝试运行它时，它只会超时服务器。你能否告诉我它看起来是否正确或是否有任何可能需要做出的改变......

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

你可以解决这个问题：

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

感谢大家的帮助。我终于能够弄清楚如何做到这一点。如果有人发现它有用，我会在下面发布我想出的内容。 derivedTable部分是我试图找出的部分。

        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

SQL联合按内部查询选择顺序，然后选择整个联合

2 个答案: