向数据集添加列以用作 XML 父节点

Question

我正在尝试从 MySQL 查询格式化 XML，以模拟客户端前端期望输入的内容。我无法控制客户需要什么，所以我必须匹配我从 Wireshark 捕获的内容。我不赞成向数据集中添加列来执行此操作，我可能只搜索和替换 XML 的添加内容，但是，我有大量非常相似但不同的查询和输出写，我更愿意做一些可以很好地扩展的事情。不幸的是，它会被丢弃代码，因为当我为此编写新的前端客户端时，我们不会跟踪当前遗留系统所做的大量数据，例如客户端 IP 地址或所谓的唯一“ActionID”您将在下面看到引用的内容，我也不必对 XML 做任何事情，这都是 MySQL 驱动的查询。

我的输出应该是这样的：

<PCBDatabaseReply>
  <SearchResult>
    <SBE_PCB_Data PCBID="53">
      <Termination ActionID="97DF" User="UName:192.168.255.255" Date="2012-09-26T13:15:51" PCBID="53">
        <Reason>Other</Reason>
      </Termination>
    </SBE_PCB_Data>
  </SearchResult>
</PCBDatabaseReply>

我的查询结果如下所示：

EventType   User    Date                PCBID   Reason 
Termination UName   2012-09-26T13:15:51 53      Other 

我的输出 XML 目前如下所示：

<PCBDatabaseReply>
  <Termination User="UName" Date="2012-09-26T13:15:51" PCBID="53">
    <EventType>Termination</EventType>
    <Reason>Other</Reason>
  </Termination>
</PCBDatabaseReply>

使用此代码：

string mysqlConnection = "server=server;\ndatabase=database;\npassword=password;\nUser ID=user;";
MySqlConnection connection = new MySqlConnection(mysqlConnection);
connection.Open();
string command = "SELECT eventtypes.EventType, events.User, DATE_FORMAT(events.DateTime,'%Y-%m-%dT%T') AS Date, pcbid.PCBID, getReasons.ItemValue AS Reason " +
                "FROM events " +
                "INNER JOIN pcbid ON events.PCBID = pcbid.PCBID " +
                "INNER JOIN eventtypes " +
                "ON events.EventType_ID = eventtypes.EventType_ID " +
                "LEFT JOIN getReasons " + 
                "ON getReasons.Event_ID = events.Event_ID " +
                "WHERE eventtypes.EventType = 'termination'";
//create fake "ActionID"
var random = new Random();
string ActionID = String.Format("{0}\"{1:X4}\"", "ActionID=", random.Next(0xffff));

MySqlDataAdapter adapter = new MySqlDataAdapter(command, connection);
DataSet dataSet = new DataSet();
adapter.Fill(dataSet);
//change upper level node name to what's expected in client-speak
dataSet.DataSetName = "PCBDatabaseReply";

//change first child node name to client-speak eventType
dataSet.Tables[0].TableName = dataSet.Tables[0].Rows[0][0].ToString();
StringWriter writer = new StringWriter();

var ds1 = dataSet.Tables[0];
DataColumn dcEventType = ds1.Columns[0];
DataColumn dcUser = ds1.Columns[1];
DataColumn dcDate = ds1.Columns[2];
DataColumn dcPCBID = ds1.Columns[3];

dcEventType.ColumnMapping = MappingType.Element;
dcUser.ColumnMapping = MappingType.Attribute;
dcDate.ColumnMapping = MappingType.Attribute;
dcPCBID.ColumnMapping = MappingType.Attribute;

dataSet.Tables[0].WriteXml(writer, true);
Console.WriteLine(writer.ToString());

我需要注入几样东西

在下面的顶部：

<SearchResult>
  <SBE_PCB_Data PCBID="53">

在 Termination 标签中：（来自代码中的虚假 ActionID）

ActionID="0xnnnn"  & append ":192.168.255.255" to the end of the user name

然后用适当的标签结束：

  </SBE_PCB_Data>
</SearchResult>

我尝试为“SBE_PCB_Data”标签添加一个虚拟列，但没有成功。

DataColumn dcSBE_PCB_Data = new DataColumn("SBE_PCB_Data", System.Type.GetType("System.String"), "SBE_PCB_Data", MappingType.Element);
dcSBE_PCB_Data.DefaultValue = "SBE_PCB_Data";
//add to the dataset
dataSet.Tables[0].Columns.Add(dcSBE_PCB_Data);
//move it to the zeroth position
dcSBE_PCB_Data.SetOrdinal(0);

这只是让它显示为：

<SBE_PCB_Data>SBE_PCB_Data</SBE_PCB_Data>

我需要它作为祖先节点将 XML 的其余部分包裹起来。

如何最好地将我需要的 XML 注入结果中？

编辑：根据下面的优秀示例进行重构 **编辑：使用最终代码更新

using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Xml.Linq;
using MySql.Data.MySqlClient;

namespace TerminationResults
{
public class SearchResult
{
    //all possible event detail tags (test items are excluded)
    public string EventType { get; set; }
    public string User { get; set; }
    public string Date { get; set; }
    public string PCBID { get; set; }
    public string EAReason { get; set; }
    public string ETReason { get; set; }
    public string Notes { get; set; }
    public string Reason { get; set; }
    public string SBEJobNumber { get; set; }
    public string SBEModelNumber { get; set; }
    public string SBEPN { get; set; }
    public string SBESerialNumber { get; set; }
    //create fake IP address since we no longer track it
    public string UserAndIP
    {
        get { return String.Format("{0}:192.168.255.255", User); }
        set {}
    }
    //create fake actionID since the originals weren't inserted into the database because they weren't unique.
    public string ActionId
    {
        get { return String.Format("{0:X4}", new Random().Next(0xffff)); }
        set {}
    }
}

internal class Program
{
    private static void Main(string[] args)
    {
        var searchResults = GetSearchResults();
        var xml = TransformList(searchResults);
        Console.WriteLine(xml);
        Console.ReadLine();
    }

    public static IEnumerable<SearchResult> GetSearchResults()
    {
        List<SearchResult> searchResults = new List<SearchResult>();
        try
        {
            const string mysqlConnection = @"server=server;
                                        database=database;
                                        password=password;
                                        User ID=username;";
            MySqlConnection conn = new MySqlConnection(mysqlConnection);
            conn.Open();
            using (conn)
            {
                string cmd = @"SELECT eventtypes.EventType, events.User, 
                    DATE_FORMAT(events.DateTime,'%Y-%m-%dT%T') AS Date,
                    pcbid.PCBID, 
                    getEAReasons.ItemValue AS EAReason,
                    getETReasons.ItemValue AS ETReason,
                    getReasons.ItemValue AS Reason, 
                    getNotes.ItemValue AS Notes,
                    getSBEJobNumbers.ItemValue AS SBEJobNumber,
                    getSBEModelNumbers.ItemValue AS SBEModelNumber,
                    getSBEPNs.ItemValue as SBEPN,
                    getSBESerialNumbers.ItemValue as SBESerialNumber
                    FROM events 
                    INNER JOIN pcbid ON events.PCBID = pcbid.PCBID 
                    INNER JOIN eventtypes 
                    ON events.EventType_ID = eventtypes.EventType_ID 
                    LEFT JOIN getEAReasons
                    ON getEAReasons.Event_ID = events.Event_ID
                    LEFT JOIN getETReasons
                    ON getETReasons.Event_ID = events.Event_ID
                    LEFT JOIN getReasons
                    ON getReasons.Event_ID = events.Event_ID
                    LEFT JOIN getNotes
                    ON getNotes.Event_ID = events.Event_ID
                    LEFT JOIN getSBEJobNumbers
                    ON getSBEJobNumbers.Event_ID = events.Event_ID
                    LEFT JOIN getSBEModelNumbers
                    ON getSBEModelNumbers.Event_ID = events.Event_ID
                    LEFT JOIN getSBEPNs
                    ON getSBEPNs.Event_ID = events.Event_ID
                    LEFT JOIN getSBESerialNumbers
                    ON getSBESerialNumbers.Event_ID = events.Event_ID
                    WHERE eventtypes.EventType = 'termination'";
                try
                {
                    using (MySqlDataAdapter adapter = new MySqlDataAdapter(cmd, conn))
                    {
                        DataSet dataSet = new DataSet();
                        adapter.Fill(dataSet);
                        DataTable ds = dataSet.Tables[0];
                        for (int row = 0; row < ds.Rows.Count; row++ )
                        {
                            SearchResult result = new SearchResult()
                                {
                                    EventType = ds.Rows[row]["EventType"].ToString(),
                                    User = ds.Rows[row]["User"].ToString(),
                                    Date = ds.Rows[row]["Date"].ToString(),
                                    PCBID = ds.Rows[row]["PCBID"].ToString(),
                                    EAReason = ds.Rows[row]["EAReason"].ToString().Any() ? ds.Rows[row]["EAReason"].ToString() : null,
                                    ETReason = ds.Rows[row]["ETReason"].ToString().Any() ? ds.Rows[row]["ETReason"].ToString() : null,
                                    Notes = ds.Rows[row]["Notes"].ToString().Any() ? ds.Rows[row]["Notes"].ToString() : null,
                                    Reason = ds.Rows[row]["Reason"].ToString().Any() ? ds.Rows[row]["Reason"].ToString() : null,
                                    SBEJobNumber = ds.Rows[row]["SBEJobNumber"].ToString().Any() ? ds.Rows[row]["SBEJobNumber"].ToString() : null,
                                    SBEModelNumber = ds.Rows[row]["SBEModelNumber"].ToString().Any() ? ds.Rows[row]["SBEModelNumber"].ToString() : null,
                                    SBEPN = ds.Rows[row]["SBEPN"].ToString().Any() ? ds.Rows[row]["SBEPN"].ToString() : null,
                                    SBESerialNumber = ds.Rows[row]["SBESerialNumber"].ToString().Any() ? ds.Rows[row]["SBESerialNumber"].ToString() : null
                                };
                            searchResults.Add(result);
                        }

                    }
                }
                catch (MySqlException ex)
                {
                    Console.WriteLine(ex);
                }
                catch(Exception ex)
                {
                    Console.WriteLine(ex);
                }

            }
        }
        catch (MySqlException ex)
        {
            Console.WriteLine(ex);
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex);
        }
        return searchResults;
    }

    public static XElement TransformSearchResult (SearchResult result)
    {
        return new XElement("SBE_PCB_Data", 
            new XAttribute("PCBID", result.PCBID),
            new XElement(result.EventType,
            new XAttribute("ActionID", result.ActionId),
            new XAttribute("User", result.UserAndIP),
            new XAttribute("Date", result.Date),
            new XAttribute("PCBID", result.PCBID),
            result.EAReason == null ? null : new XElement("EAReason", result.EAReason),
            result.ETReason == null ? null : new XElement("ETReason", result.ETReason),
            result.Reason == null ? null : new XElement("Reason", result.Reason),
            result.Notes == null ? null : new XElement("Note", result.Notes),
            result.SBEJobNumber == null ? null : new XElement("SBEJobNumber", result.SBEJobNumber),
            result.SBEModelNumber == null ? null : new XElement("SBEModelNumber", result.SBEModelNumber),
            result.SBEPN == null ? null : new XElement("SBEPN", result.SBEPN),
            result.SBESerialNumber == null ? null : new XElement("SBESerialNumber", result.SBESerialNumber)
            )
        );
    }

    public static XElement TransformList (IEnumerable<SearchResult> listOfResults)
    {
        return new XElement("PCBDatabaseReply",
            new XElement("SearchResult", 
                            from r in listOfResults
                            select TransformSearchResult(r)));
    }
}

}
必须做一些调整才能让它运行，但这个概念是合理的，我喜欢它是可扩展的。它还不能提供正确的输出，但我也可以对其进行调整。

Answer 1

好的，让我们重构一下。

我们不要尝试直接从您的数据集执行此操作，您在这里尝试在您的方法中做很多事情，它很难维护并且很难进行单元测试。

我们应该做的第一件事是创建一个 SearchResult 类，我们可以更轻松地使用它，这也是放置我们的业务规则（添加到用户的 Ip 和随机 ActionId）的方便位置，这也意味着我们可以轻松地将数据模拟到此类而无需访问数据库，然后我们可以将转换逻辑作为单元测试进行测试，而不是集成测试（速度较慢，并且具有更多依赖项）

public class SearchResult
{
    public string EventType {get ;set;}
    public string User {get ; set;}
    public DateTime Date {get;set;}
    public int PCBID {get;set;}
    public string Reason {get;set;}

    public string UserAndIP
    {
        get
        {
            return String.Format("{0}:192.168.255.255",User);
        }
    }

    public string ActionId
    {
        get
        {
            return String.Format("{0:X4}", new Random().Next(0xffff));
        }
    }
}

所以让我们重写查询以填充 SearchResult 列表而不是数据集

public IEnumerable<SearchResult> GetSearchResults()
{
    using(var conn = GetYourConnection())
    {
        conn.open();
        using(var cmd = conn.CreateCommand())
        {
            cmd.CommandText = GetYourQueryString();
            using(var reader = cmd.ExecuteReader())
            {
                while(reader.Read())
                {
                    var result = new SearchResult
                    {
                        .... populate from reader...
                    }
                    yield return result;
                }
            }           
        }
    }
}

现在我们有了一个 SearchResult 类和一个查询方法，它为我们提供了它们的列表，让我们将其转换为所需的 XML。 首先，我将从您的问题中做出一些并非 100% 清楚的假设。 （如果这些不正确，很容易修改）

1. 我假设我们正在为每个搜索创建一个搜索结果标签 从我们的查询返回的结果。这些将包含在 PCBDatabaseReply 标签。

2. xml 标签“Termination”是事件类型的值，所以我会 假设标签应该是 EventType 值。

让我们使用 Linq to XML 从 SearchResults 列表中创建 XML

首先，我们将创建一个方法来转换单个 SearchResult（SearchResult 标记的内容）

public XElement TransformSearchResult(SearchResult result)
{
    return new XElement("SearchResult",
        new XElement("SBE_PCB_Data", new XAttribute("PCBID", result.PCBID)),
        new XElement(result.EventType,
            new XAttribute("ActionID", result.ActionId),
            new XAttribute("User", result.UserAndIP),
            new XAttribute("Date", result.Date),
            new XAttribute("PCBID", result.PCBID)),
        new XElement("Reason", result.Reason));
}

其次，我们将创建转换列表的方法

public XElement TransformList(IEnumerable<SearchResult> listOfResults)
{
    return new XElement("PCBDatabaseReply", 
            from r in listOfResults
            select TransformSearchResult(r));
}

现在我们的主要调用方法就变成了……

var searchResults = GetSearchResults();
var xml = TransformList(searchResults);