Question

我有这个查询，但由于group by子句，我无法选择所有字段。

如何重新构造查询以便检索所有信息？我已经尝试过每个字段的GroupBy，但其中一些是文本。

SELECT 

    p.Pato_Id,
    p.Description,
    p.Dated
    a.Assessment_Id,
    a.Recommendation,
    Question1 = MAX(CASE WHEN r.Question_Id = 0 THEN r.Answer_Id END),
    Question2 = MAX(CASE WHEN r.Question_Id = 1 THEN r.Answer_Id END)

FROM 
    Patos p
OUTER APPLY (
    SELECT TOP 1 
        a.Assessment_Id
        , a.Recommendation
    FROM 
        Assessments a
    WHERE 
        a.Pato_Id = p.Pato_Id
    ORDER BY 
        a.Dated DESC
    ) a
JOIN 
    Replies r
ON 
    a.Assessment_Id = r.Assessment_Id

GROUP BY
    p.Pato_Id

Answer 1

尝试将文字字段转换为nvarchar(max)，然后包含group by中的所有字段，例如：

SELECT 
    p.Pato_Id,
    CAST(p.Description AS nvarchar(max)),
    p.Dated,
    a.Assessment_Id,
    a.Recommendation,
    Question1 = MAX(CASE WHEN r.Question_Id = 0 THEN r.Answer_Id END),
    Question2 = MAX(CASE WHEN r.Question_Id = 1 THEN r.Answer_Id END)
FROM Patos p
OUTER APPLY (
    SELECT TOP 1 
        a.Assessment_Id
        , a.Recommendation
    FROM Assessments a
    WHERE a.Pato_Id = p.Pato_Id
    ORDER BY a.Dated DESC
    ) a
JOIN Replies r
ON a.Assessment_Id = r.Assessment_Id
GROUP BY 
    p.Pato_Id,
    CAST(p.Description AS nvarchar(max)),
    p.Dated,
    a.Assessment_Id,
    a.Recommendation

哪个是文字栏？假设它是p.Description，你可以这样做：

SELECT sub.*, t.Description FROM
(SELECT 
    p.Pato_Id as Pato_Id,
    t.Description as Description,
    t.Dated as Dated,
    a.Assessment_Id as Assessment_Id,
    a.Recommendation as Recommendation,
    Question1 = MAX(CASE WHEN r.Question_Id = 0 THEN r.Answer_Id END),
    Question2 = MAX(CASE WHEN r.Question_Id = 1 THEN r.Answer_Id END)
FROM Patos p
OUTER APPLY (
    SELECT TOP 1 
        a.Assessment_Id
        , a.Recommendation
    FROM Assessments a
    WHERE a.Pato_Id = p.Pato_Id
    ORDER BY a.Dated DESC
    ) a
JOIN Replies r
ON a.Assessment_Id = r.Assessment_Id
GROUP BY 
    p.Pato_Id,
    a.Assessment_Id,
    a.Recommendation) AS sub
INNER JOIN Patos t ON
    t.Pato_Id = sub.Pato_Id

如果Recommendation Group By也变为：

GROUP BY 
    p.Pato_Id,
    a.Assessment_Id

你也加入了那张桌子。

从组中选择字段

1 个答案: