在SQL Server中使用XQuery比较两组XML数据

Question

假设我将员工数据存储xml在我的日志表的列中.有时,数据也会在xml存储过程的列中更新.

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>'

xml我需要显示的两个数据有一些区别,比如旧值和新值作为sql的输出

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

我只需要像上面那样展示差异.因此,请指导我如何使用XQuery比较两个xml数据,并仅在SQL Server中以上述方式显示差异.请引导我使用代码段.谢谢

Answer 1

;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