我有一个SQL查询，它提供了太多我需要的信息。我当前的查询如下所示：
USE LetterGeneration
SELECT g.LetterGenerationTemplateRequestId,
cast(H.CreatedDate as time) as Time,
s.StatusKey
FROM LetterGenerationStatusHistory H
INNER JOIN LetterGenerationStatus S
ON H.LetterGenerationStatusId = s.LetterGenerationStatusId
INNER JOIN LetterGeneration G
ON g.LetterGenerationId = h.LetterGenerationId
WHERE g.LetterGenerationTemplateRequestId IN (SELECT [LetterGenerationTemplateRequestId]
FROM [LetterGenerationTemplateRequest]
WHERE CreatedDate >= DATEADD(day,-90, GETDATE()))
AND (s.StatusKey = 'QC1'
OR s.StatusKey = 'Ready')
ORDER BY LetterGenerationTemplateRequestId, h.CreatedDate ASC
结果我看起来像这样：
LetterGenerationTemplateRequestId Time StatusKey
1732189 01:14:24.1700000 QC1
1732189 10:13:25.4730000 READY
1732190 01:14:26.6600000 QC1
1732190 01:14:26.7230000 QC1
1732190 01:14:26.7970000 QC1
1732190 01:14:26.8770000 QC1
1732190 01:14:26.9500000 QC1
1732190 01:14:27.0370000 QC1
1732190 01:14:27.1100000 QC1
1732190 04:29:17.7170000 READY
1732190 04:29:33.8500000 READY
1732190 04:29:50.7900000 READY
我想要的是每个请求ID只有1个结果，状态QC1和状态READY。理想情况下，它看起来像这样：
Request ID Time Status
1732189 1:14:24 AM QC1
1732189 10:13:25 AM READY
1732190 1:14:27 AM QC1
1732190 4:29:18 AM READY
1732191 1:14:30 AM QC1
1732191 4:39:28 AM READY
等
如何将结果限制为仅显示每个ID的1个状态结果？我已经在这里检查了一些其他问题，并尝试调整它们以适合我的查询，但我对SQL的有限知识使得它非常困难。
答案 0 :(得分：1)
您可以使用[...]
// Print a word when submit the form
view.on('post', { action: 'products' }, function(next) {
console.log('POST')
next()
})
// Get all products from db
view.on('init'...)
// Render
view.render('products')
：
row_number() SELECT t.*
FROM (SELECT g.LetterGenerationTemplateRequestId,
cast(H.CreatedDate as time) as Time,
s.StatusKey,
ROW_NUMBER() OVER (PARTITION BY g.LetterGenerationTemplateRequestId, s.StatusKey
ORDER BY H.CreatedDate DESC
) as seqnum
FROM LetterGenerationStatusHistory H INNER JOIN
LetterGenerationStatus S
ON H.LetterGenerationStatusId = s.LetterGenerationStatusId INNER JOIN
LetterGeneration G
ON g.LetterGenerationId = h.LetterGenerationId
WHERE g.LetterGenerationTemplateRequestId IN (SELECT [LetterGenerationTemplateRequestId]
FROM [LetterGenerationTemplateRequest]
WHERE CreatedDate >= DATEADD(day,-90, GETDATE())
) AND
s.StatusKey IN ('QC1', 'Ready')
) t
WHERE seqnum <= 1
ORDER BY LetterGenerationTemplateRequestId, CreatedDate ASC;
语法中的ORDER BY指定您想要的行。在这种情况下，它是最近的一行。
您可以更改＆＃34; 1＆＃34;在外部ROW_NUMBER()中，每组获得尽可能多的行数。