问题：
运行查询时，我得到了这些结果（列task_externalId）：
任务（TC229090）可以包含多行（10000,20000），但也可以只有一行（仅限10000）。
我的完整代码：
SELECT
v.voorgemeld_handmatig, v.voorgemeld, v.mac, v.orn, v.cdm, v.blo,
v.bco, v.tarcode, (v.timeslotfrom + ' - ' + v.timeslottill),
cast (case
when
(Select ac2.actionSpecificationName
From [COMTECdefault].[dbo].[task] t2
Join [COMTECdefault].[dbo].[actionKind] ak2 On t2.id_actionKind = ak2.id_actionKind
Join [COMTECdefault].[dbo].[actionSpecification] ac2 On ak2.id_actionSpecification = ac2.id_actionSpecification
where t2.task_externalId = (left(t.task_externalId, 15) + '2')) = 'laden'
then 'Vol'
else 'Leeg'
end as text) as IMPORT,
t.task_externalId, a.addressName, a.cityName,
CONVERT(DATE, t.from_date) as [Date],
CONVERT(varchar(8), CONVERT(TIME, t.from_date)) as [Tijd],
res.resourceName, resk.resourceKindName, r.shipOwner,
t.reference,
(Select resourceName
From [COMTECdefault].[dbo].[resource] r5
Left Outer Join [COMTECdefault].[dbo].resourceKind rk5 On rk5.id_resourceKind = r5.id_resourceKind
Where (id_resource = SUBSTRING(pt.StartResources, 0, CHARINDEX(',', pt.StartResources))
or id_resource = PARSENAME(REPLACE(SUBSTRING(pt.StartResources, CHARINDEX(',', pt.StartResources) + 1, LEN(pt.StartResources)), ',', '.'), 4)
or id_resource = PARSENAME(REPLACE(SUBSTRING(pt.StartResources, CHARINDEX(',', pt.StartResources) + 1, LEN(pt.StartResources)), ',', '.'), 3)
or id_resource = PARSENAME(REPLACE(SUBSTRING(pt.StartResources, CHARINDEX(',', pt.StartResources) + 1, LEN(pt.StartResources)), ',', '.'), 2)
or id_resource = PARSENAME(REPLACE(SUBSTRING(pt.StartResources, CHARINDEX(',', pt.StartResources) + 1, LEN(pt.StartResources)), ',', '.'), 1))
and r5.id_resourceKind = 51),
udo.udf_Gewicht, udo.udf_Zegelnummer,
cast (case when a.addressName = 'APM Terminal 2'
then case when udo.udf_Zegelnummer IS NULL
then 0
else 1
end
when a.addressName IN ('ect delta', 'Euromax Terminam C.V.', 'Euromax Terminal')
then case when udo.udf_Gewicht = 0
then 0
else 1
end
else 1
end as bit) as [voormelden],
v.foutcode, v.foutcode_tekst, v.V_door
FROM
[COMTECdefault].[dbo].[task] t
JOIN
[COMTECdefault].[dbo].[actionKind] ak ON t.id_actionKind = ak.id_actionKind
JOIN
[COMTECdefault].[dbo].[actionSpecification] ac ON ak.id_actionSpecification = ac.id_actionSpecification
LEFT OUTER JOIN
[COMTECdefault].[dbo].[resourceOrder] ro ON t.id_order = ro.id_order
LEFT OUTER JOIN
[COMTECdefault].[dbo].[resource] res ON ro.id_resource = res.id_resource
LEFT OUTER JOIN
[COMTECdefault].[dbo].[resourceKind] resk ON res.id_resourceKind= resk.id_resourceKind
LEFT OUTER JOIN
[COMTECdefault].[dbo].[address] a ON t.id_address = a.id_address
LEFT OUTER JOIN
[COMTECdefault].[dbo].[resourceOrder] r ON t.id_order = r.id_order
LEFT OUTER JOIN
[COMTECdefault].[dbo].[order] o ON o.id_order = r.id_order
LEFT OUTER JOIN
[COMTECdefault].[dbo].[voormelden] v ON v.id_task_otd = t.task_externalId
LEFT OUTER JOIN
[COMTECdefault].[dbo].[ud_order] udo ON udo.id_order = t.id_order
LEFT OUTER JOIN
[COMTECdefault].[dbo].[plannedTask] pt on t.id_task = pt.id_task
WHERE
(pt.id_Task IS NULL OR pt.taskstate <> 'finished')
AND (v.canceled IS NULL OR v.canceled = 0)
AND left(res.resourceName, 4) <> 'XXXU'
AND t.canceled = 0
AND (t.from_date <= '2016-11-24 23:59:59')
AND (ac.actionSpecificationName = 'inleveren')
AND a.addressName IN ('APM Terminal 1','APM Terminal 2', 'ect delta', 'rwg', 'Euromax Terminam C.V.', 'Euromax Terminal')
ORDER BY
res.resourceName, a.addressName, t.task_externalId
我只想在20000任务存在时显示它。否则显示10000.
提前致谢。
答案 0 :(得分：1)
我不会触及所有文本，可能会缩小所有联接等等，但这是使用task_exteralid列执行所需操作的模式。
DECLARE @Table AS TABLE (task_externalid VARCHAR(100))
INSERT INTO @Table VALUES
('TC229090-10000-3')
,('TC229090-20000-3')
,('TC229830-10000-3')
,('TC229685-10000-3')
;WITH cte AS (
SELECT
*
,RowNumber = ROW_NUMBER() OVER (PARTITION BY
LEFT(task_externalid,CHARINDEX('-',task_externalid) - 1)
ORDER BY task_externalid DESC)
FROM
@Table
)
SELECT *
FROM
cte
WHERE
RowNumber = 1
ROW_NUMBER的大多数LEFT task_exteralid
task_exteralid DESC