如何比较mssql中的两个xml文件

Question

我有 2 个类型的文件：

@xmlAuthors1 XML =N'
       <Author name="John" surname="Clinton" />
       <Author name="Bill" surname="Skobov" />
       <Author name="John" surname="Lokwood" />;

@xmlAuthors2 XML =N'
       <Author name="Bill" surname="Skobov" />
       <Author name="John" surname="Clinton" />
       <Author name="John" surname="Lokwood" />;

如何发现它们相等？比较文件 1 的每一行与文件 2 的每一行

Answer 1

例如，您可以像这样比较它们：

DECLARE @xmlAuthors1 XML = N'
               <Author name="John" surname="Clinton" />
               <Author name="Bill" surname="Skobov" />
               <Author name="John" surname="Lokwood" />',
        @xmlAuthors2 XML =N'
               <Author name="Bill" surname="Skobov" />
               <Author name="Johns" surname="Clinton" />
               <Author name="John" surname="Lokwood" />'


SELECT *
FROM (
    SELECT  CAST(x1.t.query('.') as nvarchar(max)) as x1,
            CAST(x2.t.query('.') as nvarchar(max)) as x2
    FROM @xmlAuthors1.nodes('/*') as x1(t)
    FULL OUTER JOIN @xmlAuthors2.nodes('/*') as x2(t)
        ON CAST(x1.t.query('.') as nvarchar(max)) = CAST(x2.t.query('.') as nvarchar(max))
) as x
WHERE x1 is null or x2 is null

如果相等就没有输出

Answer 2

这是我的方法：

.query(.data()).value() 有一个很好的技巧，可以将所有内部文本检索为空格分隔的字符串。这使得在字符串级别上进行比较变得容易......

我更改了您的输入以包含更多测试用例：

DECLARE @xmlAuthors1 XML = N'
               <Author name="John" surname="Clinton" />
               <Author name="Bill" surname="Different" />
               <Author name="John" surname="Lokwood" />
               <Author name="Test" surname="it" />',
        @xmlAuthors2 XML =N'
               <Author name="Bill" surname="Skobov" />
               <Author name="John" surname="Clinton" />
               <Author name="John" surname="Lokwood" />
               <Author name="One" surname="More" />';

SELECT ISNULL(Author1,Author2) AS Author
      ,CASE WHEN Author1 IS NULL THEN 'Exists in 2' ELSE 'Exists in 1' END AS [Source]
FROM
(
    SELECT B.query('data(@*)').value('.','varchar(max)') AS Author1
    FROM @xmlAuthors1.nodes('/Author') AS A(B)
) AS tbl1
FULL OUTER JOIN
( 
    SELECT B.query('data(@*)').value('.','varchar(max)') As Author2
    FROM @xmlAuthors2.nodes('/Author') AS A(B)
)AS tbl2 ON Author1=Author2
WHERE Author1 IS NULL OR Author2 IS NULL

如果你想找到两者相等的，你可以使用这个

SELECT B.query('data(@*)').value('.','varchar(max)') AS EqualAuthor
FROM @xmlAuthors1.nodes('/Author') AS A(B)
INTERSECT
SELECT B.query('data(@*)').value('.','varchar(max)') 
FROM @xmlAuthors2.nodes('/Author') AS A(B)

Answer 3

这取决于平等对你意味着什么。我会比较数据如下：

DECLARE @xmlAuthors1 XML =N'
       <Author name="John" surname="Clinton" />
       <Author name="Bill" surname="Skobov" />
       <Author name="John" surname="Lokwood" />
       <Author name="John" surname="Blurred" />';

DECLARE @xmlAuthors2 XML =N'
       <Author name="Bill" surname="Skobov" />
       <Author name="John" surname="Clinton" />
       <Author name="John" surname="Lokwood" />';

WITH Xml1 AS
(
    SELECT
        T.A.value('@name', 'varchar(20)') Name,
        T.A.value('@surname', 'varchar(20)') Surname
    FROM @xmlAuthors1.nodes('/Author') T(A)
), Xml2 AS
(
    SELECT
        T.A.value('@name', 'varchar(20)') Name,
        T.A.value('@surname', 'varchar(20)') Surname
    FROM @xmlAuthors2.nodes('/Author') T(A)
)
SELECT 'Unique in 1' [Description], * FROM (SELECT * FROM Xml1 EXCEPT SELECT * FROM Xml2) Q1
UNION ALL
SELECT 'Unique in 2' [Description], * FROM (SELECT * FROM Xml2 EXCEPT SELECT * FROM Xml1) Q2

这个特定的例子产生：

Description   Name    Surname
-----------   ----    -------
Unique in 1   John    Blurred