创建一个查询，使用过滤器更快地获取数据 XML

Question

我正在使用 SQL 服务器 2014，试图从 SQL 服务器中以分层结构获取 xml， `

WITH
parent as (select ModelId,ParentIdFK,ModelName,Expanded,SortOrder from model where NodeLevel =  0),
FirstNode as (select ModelId,ParentIdFK,ModelName,Expanded,SortOrder from model where ParentIdFK in(select ModelId from parent)),
SecondNode as (select ModelId,ParentIdFK,ModelName,Expanded,SortOrder from model where ParentIdFK in(select ModelId from FirstNode)),
ThirdNode as (select ModelId,ParentIdFK,ModelName,Expanded,SortOrder from model where ParentIdFK in(select ModelId from SecondNode)),
FouthNode as (select ModelId,ParentIdFK,ModelName,Expanded,SortOrder from model where ParentIdFK in(select ModelId from ThirdNode)),
FifthNode as (select ModelId,ParentIdFK,ModelName,Expanded,SortOrder from model where ParentIdFK in(select ModelId from FouthNode)),
SixthNode as (select ModelId,ParentIdFK,ModelName,Expanded,SortOrder from model where ParentIdFK in(select ModelId from FifthNode)),
XmlData as (select (select p.*,L1.*,L2.*,L3.*,L4.*,L5.*,L6.* from parent p
left join FirstNode L1 on  L1.ParentIdFK =p.ModelId 
left join SecondNode L2 on L2.ParentIdFK=L1.ModelId
left join ThirdNode L3 on L3.ParentIdFK=L2.ModelId
left join FouthNode L4 on L4.ParentIdFK=L3.ModelId
left join FifthNode L5 on L5.ParentIdFK=L4.ModelId
left join SixthNode L6 on L6.ParentIdFK=L5.ModelId
for xml auto , ROOT('ModelLines'),type) as XMLDataModel) 
(select @data = XMLDataModel from XmlData)

`

然后我输出为

  <model ModelId="11" ParentIdFK="3" ModelName="Sedans" Expanded="0" SortOrder="1">
      <model ModelId="14" ParentIdFK="11" ModelName="328i Sedan" Expanded="0" SortOrder="1">
        <model>
          <model />
        </model>
      </model>
      <model ModelId="15" ParentIdFK="11" ModelName="328xi Sedan" Expanded="0" SortOrder="2">
        <model>
          <model />
        </model>
      </model>
      <model ModelId="16" ParentIdFK="11" ModelName="335i Sedan" Expanded="0" SortOrder="3">
        <model>
          <model />
        </model>
      </model>
      <model ModelId="167" ParentIdFK="11" ModelName="Sheilas Model" Expanded="0" SortOrder="3">
        <model>
          <model />
        </model>
      </model>
      <model ModelId="289" ParentIdFK="11" ModelName="335xi Sedan" Expanded="0" SortOrder="3">
        <model>
          <model />
        </model>
      </model>
    </model>
    <model ModelId="12" ParentIdFK="3" ModelName="Sports Wagon" Expanded="0" SortOrder="2">
      <model ModelId="17" ParentIdFK="12" ModelName="328xi Sports Wagon" Expanded="0" SortOrder="1">
        <model>
          <model />
        </model>
      </model>
      <model ModelId="18" ParentIdFK="12" ModelName="328i Sports Wagon" Expanded="0" SortOrder="2">
        <model>
          <model />
        </model>
      </model>
      <model ModelId="214" ParentIdFK="12" ModelName="Convertible" Expanded="0" SortOrder="4">
        <model ModelId="223" ParentIdFK="214" ModelName="328i Convertible" Expanded="0" SortOrder="1">
          <model />
        </model>
        <model ModelId="224" ParentIdFK="214" ModelName="335i Convertible" Expanded="0" SortOrder="3">
          <model />
        </model>
      </model>
    </model>

这个查询太2s了，但是有很多节点没有属性

所以我尝试set @data.modify('delete //model[empty(@ModelId)]')删除这些节点这需要将近 30 秒。任何人都可以建议一种更快更好的方法来更快地获取 xmal

Answer 1

使用xml linq :

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using System.Xml.Linq;

namespace ConsoleApplication164
{
    class Program
    {
        const string FILENAME = @"c:\temp\test.xml";
        static void Main(string[] args)
        {
            XDocument doc = XDocument.Load(FILENAME);

            XElement[] models = doc.Descendants("model").ToArray();

            for (int i = models.Count() - 1; i >= 0; i--)
            {
                if (models[i].Attributes().Count() == 0)
                {
                    models[i].Remove();
                }
            }

 
        }
    }
 
}

创建一个查询，使用过滤器更快地获取数据 XML

create a query that fetch data as XML more faster with filters

c#

xml

sql

sql-server

sql-server-2014