SQL Server表到嵌套的xml文件

Question

我有一張這樣的桌子：

Action Action2  Name    Action3 Batch
--------------------------------------
add      PL    Steve    add      1
add      PL    Steve    add      3
add      PL    Steve    add      4
add      PL    Steve    add      5
add      PL    Steve    add      1
add      PL    Steve    add      3
add      PL    Steve    add      4
add      PL    Steve    add      5

並需要將其轉換為如下所示的XML文檔：

Answer 1

感謝@Isaac提供的數據腳本！

for <List> elements in <Branch> node, like <Branch><List/><List/></Branch>:

CREATE TABLE #mytable
(
   Action  VARCHAR(10),
   Action2 VARCHAR(10),
   Name    VARCHAR(50),
   Action3 VARCHAR(10),
   Batch   INT
);

INSERT INTO #mytable(Action,Action2,Name,Action3,Batch) 
VALUES 
('add','PL','Steve','add',1),
('add','PL','Steve','add',3),
('add','PL','Steve','add',4),
('add','PL','Steve','add',5),
('add','PL','Steve','add',1),
('add','PL','Steve','add',3),
('add','PL','Steve','add',4),
('add','PL','Steve','add',5);


INSERT INTO #mytable(Action,Action2,Name,Action3,Batch) 
VALUES 
('update','PL','John','insert',5),
('update','PL','Paul','insert',1),
('update','PL','Chris','delete',3),
('update','PL','Mary','update',4),
('update','PL','Jane','delete',5);


select a1.Action as '@Action', s.brancexml as '*'
from
(
select distinct Action
from #mytable
) as a1
cross apply 
(
    select
    (
        select a2.Action2 AS '@Action', a2.Name as '@Name', x.listxml as     '*'
        from
    (
        select distinct Action2, Name
        from #mytable AS b
        where b.Action = a1.Action
    ) AS a2
    cross apply
    (
        select
        (
            select distinct c.Action3 as '@Action', c.Batch as '@Batch'
            from #mytable AS c
            where c.Action = a1.Action AND c.Action2 = a2.Action2 AND c.Name = a2.Name
            for xml path('List'), type
        ) AS listxml
    ) as x
    for xml path('Brance'), type
    ) as brancexml
) as s
for xml path('Start'), root('Entries'), type

Answer 2

您已經有了一個解決方案，但這可能會更簡單一些：

CREATE TABLE #mytable
(
   Action  VARCHAR(10),
   Action2 VARCHAR(10),
   Name    VARCHAR(50),
   Action3 VARCHAR(10),
   Batch   INT
);

INSERT INTO #mytable(Action,Action2,Name,Action3,Batch) 
VALUES 
('add','PL','Steve','add',1),
('add','PL','Steve','add',3),
('add','PL','Steve','add',4),
('add','PL','Steve','add',5),
('update','PL','John','insert',5),
('update','PL','Paul','insert',1),
('update','PL','Chris','delete',3),
('update','PL','Mary','update',4),
('update','PL','Jane','delete',5);

SELECT mt1.[Action] AS [@Action]
      ,(
        SELECT mt2.Action2 AS [@Action]
              ,mt2.[Name] AS [@Name]
              ,(
                SELECT mt3.Action3 AS [@Action]
                      ,mt3.Batch AS [@Batch]
                FROM #mytable mt3
                WHERE mt3.[Action]=mt1.[Action]
                  AND mt3.Action2=mt2.Action2
                  AND mt3.[Name]=mt2.[Name]
                FOR XML PATH('List'),TYPE        
               )
        FROM #mytable mt2
        WHERE mt2.[Action]=mt1.[Action]
        GROUP BY mt2.Action2,mt2.[Name]
        FOR XML PATH('Brance'),TYPE
       )
FROM #mytable mt1
GROUP BY mt1.[Action]
FOR XML PATH('Start'),ROOT('Entries');

簡而言之：

我們使用級聯的相關子查詢，每個子查詢返回嵌套結構的一個片段。
使用,TYPE將其返回為XML，否則您將獲得轉義的文本。
使用GROUP BY允許我們僅返回一次嵌套數據。

這不會很快...在WHERE使用的列索引將為您提供幫助。