Xml中查找最大值！

myghy 2003-03-17 02:54:49

请如何在Xml中查找出最大的数据，
能用类似SQL语句（Select Max(bh) From Table)查出吗？

...全文

144 22 打赏收藏转发到动态举报

写回复

用AI写文章

22 条回复

切换为时间正序

请发表友善的回复…

发表回复

saucer 2003-03-19

打赏
举报

http://www.w3schools.com/xpath/

xxcw 2003-03-19

打赏
举报

什么地方有这方面的说明，学习学习！

saucer 2003-03-19

打赏
举报

XmlNode node = xmldoc.SelectSingleNode("ROOT/Bh[Id='10001']/List/QTY[not(. < ../..//QTY)]");

"../..//QTY" says, find the grand-parent's all descendant QTYs , this grand-parent is Bh node with its child Id node = '10001'

XPath is very context dependent, you have to know your xml

myghy 2003-03-19

打赏
举报

象这样的行吗？要取出Id='10001'中的QTY最大值,怎么取啊？
<ROOT>
<Bh>
<Id>10001</Id>
<Name>aaa</Name>
<List>
<Xh>1001</Xh>
<QTY>12</QTY>
</List>
<List>
<Xh>1002</Xh>
<QTY>1</QTY>
</List>
<List>
<Xh>1002</XH>
<QTY>25</QTY>
</List>
<List>
<Xh>1003</Xh>
<QTY>1</QTY>
</List>
<List>
<Xh>1004</Xh>
<QTY>900</QTY>
</List>
</Bh>
</ROOT>

myghy 2003-03-19

打赏
举报

To 思归大侠
XMl的格式必须象你这样规范才能使用吗？

csdnshao 2003-03-18

打赏
举报

用xpath的max（）函数

saucer 2003-03-18

打赏
举报

XmlNode node = xmldoc.SelectSingleNode("ROOT/Bh[Id='10001']/List/QTY[not(. < ../QTY)]");

saucer 2003-03-18

打赏
举报

if your XML is very regular, read it into a DataSet and use DataView's RowFilter property

DataView dv = new DataView(ds.Tables["sales"]);
dv.RowFilter = "QTY = MAX(QTY)";
for (int i=0; i < dv.Count; i++)
System.Console.WriteLine(dv[i]["QTY"]);

大健 2003-03-18

打赏
举报

学习

myghy 2003-03-18

打赏
举报

如果要找Id='10001'中QTY的最大值，怎么写？

saucer 2003-03-18

打赏
举报

try

XmlNode node = xmldoc.SelectSingleNode("ROOT/Bh/List/QTY[not(. < ../QTY)]");

saucer 2003-03-18

打赏
举报

because your xml is invalid?

<ROOT>
<Bh>
<Id>10001</Id>
<Name>aaa</Name>
<List>
<QTY>12</QTY>
<QTY>1</QTY>
<QTY>25</QTY>
<QTY>1</QTY>
<QTY>900</QTY>
<QTY>Text</QTY>
</List>
</Bh>
</ROOT>

myghy 2003-03-18

打赏
举报

不对啊！Node为nothing?

myghy 2003-03-18

打赏
举报

如果要找确认第二层下第三层的最大值，怎么写？

<ROOT>
<Bh>
<Id>10001<Id>
<Name>aaa</Name>
<List>
<QTY>12</QTY>
<QTY>1</QTY>
<QTY>25</QTY>
<QTY>1</QTY>
<QTY>900</QTY>
<QTY>Text</QTY>
</list>
</Bh>
...
</ROOT>

saucer 2003-03-18

打赏
举报

max() is not supported in XSLT 1.0

try

1. TestMax.xml:
<ROOT>
<QTY>12</QTY>
<QTY>1</QTY>
<QTY>25</QTY>
<QTY>1</QTY>
<QTY>900</QTY>
<QTY>Text</QTY>
</ROOT>

2. TestMax.cs:

using System;
using System.Xml;

class TestMax
{
public static void Main(string[] args)
{
XmlDocument xmldoc = new XmlDocument();
xmldoc.Load("TestMax.xml");
XmlNode node = xmldoc.SelectSingleNode("//QTY[not(. < //QTY)]");
if (node != null)
Console.WriteLine(node.InnerText);
}
}

myghy 2003-03-18