Question

以下代码在SQL Server中运行

declare @x xml = '<r x="x">
<s a="1" />
<s a="2" />
<s a="deleted" />
</r>
<r x="y">
<s a="3" />
<s a="4" />
<s a="deleted" />
</r>'

select @x.query('
for $r in /r 
for $s in $r[s/@a != "deleted"] 
let $z := $s (: Need to bring @x from <r> to <s> :)
return
<s>
{$z} (: need to use $z in many places :)
</s>
')

返回

<s>
  <r x="x">
    <s a="1" />
    <s a="2" />
    <s a="deleted" />
  </r>
</s>
<s>
  <r x="y">
    <s a="3" />
    <s a="4" />
    <s a="deleted" />
  </r>
</s>

但是，$z中的预期值应为

    <s a="1" x="x" />
    <s a="2" x="x" />
    <s a="3" x="y" />
    <s a="4" x="y" />

我需要实施

需要将flatmap应用于多个XML部分和

编辑：可以使用for $s in $r/s[@a != "deleted"]
在x的最终作业中将<r>的{{1}}属性带到<s>。

更新我需要执行SQL Server不支持的以下内容吗？

$z

Answer 1

declare @x xml = '<r x="x">
<s a="1" />
<s a="2" />
<s a="deleted" />
</r>
<r x="y">
<s a="3" />
<s a="4" />
<s a="deleted" />
</r>';

select @x.query('
    <s>
    {
        for $r in /r 
        for $s in $r/s[@a != "deleted"] (: Need to delete <s> which @a is "deleted" :)
        let $z := $s (: Need to bring @x from <r> to <s> :)
        return
        <s a="{$z/@a}" x="{$r/@x}" /> (: Some other code need to use $z:)
    }
    </s>
    ');

输出：

<s>
  <s a="1" x="x" />
  <s a="2" x="x" />
  <s a="3" x="y" />
  <s a="4" x="y" />
</s>

flatmap xml部分并将父属性带到子节点？

1 个答案: