我有以下触发器:
ALTER trigger tr_mytable_audit on mytable after insert, update, delete
as
SELECT *
FROM
(SELECT *
FROM inserted
UNION
SELECT *
FROM deleted) as Rows
FOR XML RAW, ELEMENTS
GO
目前插入和删除的输出如下:
<row>
<id>1</id>
<column1>test</column1>
<column2>62</column2>
</row>
对于更新,它是:
<row>
<id>1</id>
<column1>test</column1>
<column2>62</column2>
</row>
<row>
<id>1</id>
<column1>changed</column1>
<column2>62</column2>
</row>
是否可以转换xml以便它:
--Inserts
<row>
<id old="" new="1"></id>
<column1 old="" new="test"></column1>
<column2 old="" new="62"></column2>
</row>
--Deletes
<row>
<id old="1" new=""></id>
<column1 old="changed" new=""></column1>
<column2 old="62" new=""></column2>
</row>
--Updates
<row>
<id old="1" new="1"></id>
<column1 old="test" new="changed"></column1>
<column2 old="62" new="62"></column2>
</row>
更好的是,对于更新,是否可以省略未更改的列,以便xml只是:
<row>
<column1 old="test" new="changed"></column1>
</row>
修改
我设法提出了这个SQL:
ALTER trigger tr_mytable_audit on mytable after insert, update, delete
as
select d.id as 'id/old', i.id as 'id/new',
d.column1 as 'column1/old', i.column1 as 'column1/new',
d.column2 as 'column2/old', i.column2 as 'column2/new'
from inserted as i
full join deleted as d
on i.id = d.id
for xml path('row'), root('rows')
但是,对于更新,我也有未更改的列。是否可以通过改进上述SQL来过滤掉未更改的列?
答案 0 :(得分:1)
尝试加入inserted和deleted,并使用XML PATH对要生成的XML结构进行更多控制。像这样:
SELECT
ID = COALESCE(I.ID, D.ID)
, Col1 = (SELECT [@old] = D.Col1, [@new] = I.Col1
WHERE D.Col1 <> I.Col1 OR D.Col1 IS NULL OR I.Col1 IS NULL)
, Col2 = (SELECT [@old] = D.Col2, [@new] = I.Col2
WHERE D.Col2 <> I.Col2 OR D.Col2 IS NULL OR I.Col2 IS NULL)
FROM INSERTED AS I
FULL JOIN DELETED AS D
ON I.ID = D.ID
FOR XML PATH('row'), ROOT('rows')