如何在不弄乱数据的情况下将多行连接到单行？

Question

我是 sql 服务器的新手，在使用 FOR XML 代码时发现了一个问题。我的报表生成器正在使用 sql 服务器 2014。

我有 table 比如：

Field	Accessory
1.I	AA
1.I	BB
1.I	CC
1.II	AA
1.III	AA
1.III	BB
1.IV	AA
1.IV	BB
1.V	AA

并且结果要求是：

Field	Accessory
1.I	AA,BB,CC
1.II	AA
1.III	AA,BB
1.IV	AA,BB
1.V	AA

但是，我得到了这个：

Field	Accessory
1.I	AA,BB,CC,AA,AA,BB,AA,BB,AA
1.II	AA,BB,CC,AA,AA,BB,AA,BB,AA
1.III	AA,BB,CC,AA,AA,BB,AA,BB,AA
1.IV	AA,BB,CC,AA,AA,BB,AA,BB,AA
1.V	AA,BB,CC,AA,AA,BB,AA,BB,AA

这种table分组使用FOR XML路径合适吗？谢谢！

查询是：

SELECT
       Radi.Field,
       (SELECT
               Acce.AccessoryId+','
        FROM
               FieldAcce
               INNER JOIN Radi ON FieldAcce.RadiSer = Radi.RadiSer
               INNER JOIN Acce ON FieldAcce.AcceSer = Acce.AcceSer
        WHERE
               Radi.Id LIKE UPPER (@RNO)
               AND Radi.CourseID LIKE @CourseID
               AND Radi.PhaseId LIKE @PhaseID
        ORDER BY
               Radi.Field
        FOR XML PATH('')) AS [Accessory]
FROM
        FieldAcce
        INNER JOIN Radi ON FieldAcce.RadiSer = Radi.RadiSer
        INNER JOIN Acce ON FieldAcce.AcceSer = Acce.AcceSer
WHERE
        Radi.Id LIKE UPPER (@RNO)
        AND Radi.CourseID LIKE @CourseID
        AND Radi.PhaseId LIKE @PhaseID
GROUP BY
        Radi.Field
        Acce.AccessoryId
ORDER BY
        Radi.Field

新的查询如下（未添加STUFF()部分时有效）：

SELECT
    r.Field,
    STUFF(  
        (SELECT
            ', ' + Acce.AccessoryId
         FROM
            Radi
            INNER JOIN FieldAcce ON Radi.RadiSer = FieldAcce.RadiSer
            LEFT OUTER JOIN Acce ON FieldAcce.AcceSer = Acce.AcceSer
         WHERE
            Radi.Id LIKE UPPER (@RNO)
            AND Radi.CourseId LIKE @CourseID
            AND LEFT (Radi.PlanSetupId,1) LIKE @PhaseID
            AND r.Field = Radi.Field
         ORDER BY
            Radi.Field
         FOR XML PATH(''))
          ), 1, 1, '') AS [Accessory]
FROM
    Radi r
    INNER JOIN FieldAcce ON r.RadiSer = FieldAcce.RadiSer
    LEFT OUTER JOIN Acce ON FieldAcce.AcceSer = Acce.AcceSer
WHERE
    Radi.Id LIKE UPPER (@RNO)
    AND Radi.CourseId LIKE @CourseID
    AND LEFT (Radi.PlanSetupId,1) LIKE @PhaseID
    AND EXISTS
        (SELECT
            r.Field
         FROM
            Radi cry
         WHERE
            r.Field = cry.Field
            AND cry.Field NOT LIKE N'APER%')
GROUP BY
    r.Field
ORDER BY
    r.Field

附件的示例数据是

Accessory
EDW45IN
A10
A06
EDW60IN
EDW45OUT
NDS
A084

Answer 1

sub-query 应该引用主查询 Field 和 AccessoryId

SELECT
       Radi.Field,
       (SELECT
               a.AccessoryId+','
        FROM
               FieldAcce fa
               INNER JOIN Radi r ON fa.RadiSer = r.RadiSer
               INNER JOIN Acce a ON fa.AcceSer = a.AcceSer
        WHERE
               r.Id LIKE UPPER (@RNO)
               AND r.CourseID LIKE @CourseID
               AND r.PhaseId LIKE @PhaseID
               -- add the following 2 lines
               AND r.Field = Radi.Field
               AND a.AccessoryId = Acce.AccessoryId
        ORDER BY
               r.Field
        FOR XML PATH('')) AS [Accessory]
FROM
        FieldAcce
        INNER JOIN Radi ON FieldAcce.RadiSer = Radi.RadiSer
        INNER JOIN Acce ON FieldAcce.AcceSer = Acce.AcceSer
WHERE
        Radi.Id LIKE UPPER (@RNO)
        AND Radi.CourseID LIKE @CourseID
        AND Radi.PhaseId LIKE @PhaseID
GROUP BY
        Radi.Field,
        Acce.AccessoryId
ORDER BY
        Radi.Field

如何在不弄乱数据的情况下将多行连接到单行？

How to concatenate multiple rows to single row without messing up the data?

xml

nested

concatenation

sql-server-2014

coalesce