在 SQL Server 中使用 XQuery 比较两组 XML 数据 [英] Compare two sets of XML data using XQuery in SQL Server

问题描述

假设我将员工数据存储在日志表的 xml 列中.有时，数据也会从存储过程的 xml 列中更新.

Suppose I store employee data in a xml column in my log table. Sometimes data is also updated in the xml column from a stored procedure.

这是示例示例

DECLARE @XML1 XML
DECLARE @XML2 XML

SET @XML1 = 
'<NewDataSet> 
<Employee>
<EmpID>1005</EmpID>
<Name> keith </Name>
<DOB>12/02/1981</DOB>
<DeptID>ACC001</DeptID>
<Salary>10,500</Salary>
</Employee>
</NewDataSet>'

SET @XML2 = 
'<NewDataSet> 
<Employee>
<EmpID>1006</EmpID>
<Name> keith </Name>
<DOB>05/02/1981</DOB>
<DeptID>ACC002</DeptID>
<Salary>10,900</Salary>
</Employee>
</NewDataSet>'

在两个 xml 数据中存在一些差异，我需要像旧值一样显示这些数据新值作为 sql 的输出

There is some difference in two the xml data which I need to show like old value & new value as a output of sql

Old Value             New Value
---------             ---------
1005                  1006
12/02/1981            05/02/1981
ACC001                ACC002
10,500                10,900

我只需要像上面一样显示差异.所以请指导我如何使用 XQuery 比较两个 xml 数据，并在 SQL Server 中仅以上述方式显示差异.请用代码片段指导我.谢谢

I just need to show the difference like above. So please guide me how to compare two xml data using XQuery and show the difference only in the above fashion in SQL Server. Please guide me with code snippet. thanks

推荐答案

;with XML1 as
(
  select T.N.value('local-name(.)', 'nvarchar(100)') as NodeName,
         T.N.value('.', 'nvarchar(100)') as Value
  from @XML1.nodes('/NewDataSet/Employee/*') as T(N)
),
XML2 as
(
  select T.N.value('local-name(.)', 'nvarchar(100)') as NodeName,
         T.N.value('.', 'nvarchar(100)') as Value
  from @XML2.nodes('/NewDataSet/Employee/*') as T(N)
)
select coalesce(XML1.NodeName, XML2.NodeName) as NodeName, 
       XML1.Value as Value1, 
       XML2.Value as Value2
from XML1
  full outer join XML2
    on XML1.NodeName = XML2.NodeName
where coalesce(XML1.Value, '') <> coalesce(XML2.Value, '')    

结果:

NodeName             Value1               Value2
-------------------- -------------------- --------------------
EmpID                1005                 1006
DOB                  12/02/1981           05/02/1981
DeptID               ACC001               ACC002
Salary               10,500               10,900

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