在 C# 中更改 Excel Power Query 连接字符串

ivc*_*ubr 5 c# excel powerquery

在 Excel Power Query 文件中,数据连接可以来自 SQL 服务器。我们有大量按名称指定 SQL 服务器的文件,并且该服务器将退役。我们需要更新连接以用新的服务器名称替换旧的服务器名称。这可以通过打开 Excel 文件、浏览查询并手动编辑服务器名称来实现。由于有大量文件,因此需要使用 C# 执行此操作。下图显示了您可以手动更新的输入字段(已删除名称)。

SQL 连接表单

首先通过解压缩 Excel 文件并浏览文件夹下的内容,xl > connections.xml我原以为它会在那里指定连接,但它只说$Workbook$

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<connections xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main">
  <connection id="1" keepAlive="1" name="Query" description="Connection to the query in the workbook." type="5" refreshedVersion="6" background="1" saveData="1">
    <dbPr connection="Provider=Microsoft.Mashup.OleDb.1;Data Source=$Workbook$;Location=&quot;table&quot;" command="SELECT * FROM [table]"/>
  </connection>
</connections>
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MDSN 表格上有对这个主题的引用,Will Gregg 提供的答案说:

外部数据源连接信息存储在自定义部件中的 XLSX 包中。您可以在包的 customXML 文件夹下找到自定义部件。例如:customXml\iem1.xml。

item1.xml 中包含一个元素。元素的定义可以在 [MS-QDEFF]:查询定义文件格式文档 ( https://msdn.microsoft.com/en-us/library/mt577220(v=office.12).aspx ) 中找到。

为了处理元素的数据,您需要按照 [MS-QDEFF]:查询定义文件格式文档中的描述对内容进行解码。

一旦数据被解码,您将需要检查 PackagePart 的内容。在该包中,您将在 Forumlas\Section1.m 部分中找到外部数据连接信息。

这有助于将我指向item.xml文件customXml夹中的文件,但没有提供有关如何解码DataMashup对象中信息的任何详细信息。答案确实提到该[MS-QDEFF]: Query Definition File Format文档可在有关查询定义格式的主要文章的链接中找到。乍一看,本文档中的信息可能显得密集而复杂。

在 Stack Overflow 上有 6 个问题提到DataMashup,其中 4 个与 Power BI 相关,虽然与此问题相似但不相同。下面列出了每个问题的链接:

其他 2 个问题更相关,因为它们询问的是 Excel 而不是 Power BI,我将在下面讨论:

  1. 此问题询问如何使用 VBA 删除 Power Query 查询的自定义 XML 数据。我不想删除查询而是更新连接字符串,我想在 C# 而不是 VBA 中执行此操作。问题显示了使用宏记录器的结果,我不想打开每个 Excel 文件来运行 VBA 宏。
  2. 这个问题询问如何查找查询信息并且遇到了与$Workbook$我相同的问题。在 Axel Richter 的评论中,他说In *.xlsx/customXml/ you will find a item1.xml which contains a DataMashup element which contains a base64Binary which is the binary query definition file. I have no clue how to work with that. That's why only a comment and not a answer.一年多后,Tom Jebo 添加了一个答案,指向我发现的开放规范细节,但没有提供有关如何操作DataMashup对象的解决方案。我将此添加为一个新问题,因为此问题希望解决与我不同的问题,并且它也在寻找 JavaScript 中的解决方案。

解码DataMashup对象、更改服务器名称,然后将更新的连接保存回 Excel 文件的最佳方法是什么?

在Jeff Atwood 于 2011 年 7 月 1 日发表的这篇博文中,鼓励提出和回答您自己的问题。此外,此页面形成 Stack Overflow 帮助中心解决了相同的问题。我决定在 C# 中发布一个完整的工作解决方案供其他人修改和使用,希望可以节省他们需要通过我所做的所有工作来进行污泥处理的时间。

ivc*_*ubr 7

正如问题中提到的,最有用的文档是[MS-QDEFF]: Query Definition File Format. 我将在此处包含本文档中最相关的部分,但如果需要,请参阅原始文档。下面显示了带有DataMashupMicrosoft 提供的示例 XML 。这是一个简短的查询,但如果您打开customXml > item1.xml文件,则会出现类似的情况。

<DataMashup sqmid="7690c5d6-5698-463c-a560-a0093d4f6332"
    xmlns="http://schemas.microsoft.com/DataMashup">
  AAAAAEUDAABQSwMEFAACAAgAta0pR62KRJynAAAA+QAAABIAHABDb25maWcvUGFja2FnZS54bWwgohgA
  KKAUAAAAAAAAAAAAAAAAAAAAAAAAAAAhY9NDoIwGESvQrqnP4jGkI+ycCuJCdG4bUqFRiiGFsvdXHgkr
  yCJYti5nMmb5M3r8YRsbJvgrnqrO5MihikKlJFdqU2VosFdwi3KOByEvIpKBRNsbDJanaLauVtCiPce+
  xXu+opElDJyzveFrFUrQm2sE0Yq9FuV/1eIw+kjwyMcxTimmzVmMWVA5h5ybRbMpIwpkEUJu6FxQ6+4M
  uGxADJHIN8b/A1QSwMEFAACAAgAta0pRw/K6aukAAAA6QAAABMAHABbQ29udGVudF9UeXBlc10ueG1sI
  KIYACigFAAAAAAAAAAAAAAAAAAAAAAAAAAAAG2OSw7CMAxErxJ5n7qwQAg1ZQHcgAtEwf2I5qPGReFsL
  DgSVyBtd4ilZ+Z55vN6V8dkB/GgMfbeKdgUJQhyxt961yqYuJF7ONbV9Rkoihx1UUHHHA6I0XRkdSx8I
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  cQkbZR2IXEZXn8BUEsDBBQAAgAIALWtKUdi3rmEPAAAAEsAAAATABwARm9ybXVsYXMvU2VjdGlvbjEub
  SCiGAAooBQAAAAAAAAAAAAAAAAAAAAAAAAAAAArTk0uyczPUwiG0IbWvFy8XMUZiUWpKQqBpalFlYYKt
  go5qSW8XApAEJxfWpScChQx1Dbk5crMQxa1BgBQSwECLQAUAAIACAC1rSlHrYpEnKcAAAD5AAAAEgAAA
  AAAAAAAAAAAAAAAAAAAQ29uZmlnL1BhY2thZ2UueG1sUEsBAi0AFAACAAgAta0pRw/K6aukAAAA6QAAA
  BMAAAAAAAAAAAAAAAAA8wAAAFtDb250ZW50X1R5cGVzXS54bWxQSwECLQAUAAIACAC1rSlHYt65hDwAA
  ABLAAAAEwAAAAAAAAAAAAAAAADkAQAARm9ybXVsYXMvU2VjdGlvbjEubVBLBQYAAAAAAwADAMIAAABtA
  gAAAAA0AQAA77u/PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0idXRmLTgiPz48UGVybWlzc2lvb
  kxpc3QgeG1sbnM6eHNpPSJodHRwOi8vd3d3LnczLm9yZy8yMDAxL1hNTFNjaGVtYS1pbnN0YW5jZSIge
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  DEiIC8+PEVudHJ5IFR5cGU9IlJlY292ZXJ5VGFyZ2V0Um93IiBWYWx1ZT0ibDEiIC8+PEVudHJ5IFR5c
  GU9Ik5hbWVVcGRhdGVkQWZ0ZXJGaWxsIiBWYWx1ZT0ibDAiIC8+PEVudHJ5IFR5cGU9IkZpbGxUYXJnZ
  XQiIFZhbHVlPSJzUXVlcnkxIiAvPjxFbnRyeSBUeXBlPSJCdWZmZXJOZXh0UmVmcmVzaCIgVmFsdWU9I
  mwxIiAvPjxFbnRyeSBUeXBlPSJGaWxsU3RhdHVzIiBWYWx1ZT0ic0NvbXBsZXRlIiAvPjxFbnRyeSBUe
  XBlPSJRdWVyeUlEIiBWYWx1ZT0iczdlMDQzNjJlLTkyZjUtNGQ4Mi04YjA3LTI3NjFlYWY2OGFlNSIgL
  z48L1N0YWJsZUVudHJpZXM+PC9JdGVtPjxJdGVtPjxJdGVtTG9jYXRpb24+PEl0ZW1UeXBlPkZvcm11b
  GE8L0l0ZW1UeXBlPjxJdGVtUGF0aD5TZWN0aW9uMS9RdWVyeTEvU291cmNlPC9JdGVtUGF0aD48L0l0Z
  W1Mb2NhdGlvbj48U3RhYmxlRW50cmllcyAvPjwvSXRlbT48L0l0ZW1zPjwvTG9jYWxQYWNrYWdlTWV0Y
  WRhdGFGaWxlPhYAAABQSwUGAAAAAAAAAAAAAAAAAAAAAAAA2gAAAAEAAADQjJ3fARXREYx6AMBPwpfrA
  QAAACLWGAG5O6FHjkAGtB+m5EQAAAAAAgAAAAAAA2YAAMAAAAAQAAAAaH8KNe2ciHwfVosIvSCr6gAAA
  AAEgAAAoAAAABAAAAA40fOKWe6kmTAWJSBXs4cYUAAAAPNy7uF6Dtr9PvADu+eZdeV7JutpIQTh41qqT
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  6Jm8C98hVmJBo638e4Qk65V
</DataMashup>
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这个对象的值被编码在一个Base64字符串中。如果您不熟悉 Base 64,这篇 Wikipedia文章将是一个不错的起点。解决方案的第一步是打开 XML 文档并将其转换为它的byte表示形式。这可以按如下方式完成:

string file = @"\customXml\item1.xml"; // or wherever your xml file is
XDocument doc = XDocument.Load(file);

byte[] dataMashup = Convert.FromBase64String(doc.Root.Value);
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注意:在此答案底部提供的完整示例中,所有操作都在内存中完成。

来自 Microsoft 定义文档:

版本(4 个字节):必须设置为 0 的无符号整数。

封装部件长度(4 个字节):无符号整数,指定封装部件字段的长度。

包部分(变量):可变长度的二进制流(第 2.3 节)。

权限长度(4 个字节):指定权限字段长度的无符号整数。

权限(变量):可变长度的二进制流(第 2.4 节)。

元数据长度(4 字节):指定元数据字段长度的无符号整数。

元数据(变量):可变长度的二进制流(第 2.5 节)。

权限绑定长度(4 字节):指定权限绑定字段长度的无符号整数。

权限绑定(变量):可变长度的二进制流(第 2.6 节)。

由于定义其内容长度的每个字段都是 4 个字节,因此我定义了一个常量

private const int FIELDS_LENGTH = 4;
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然后可以找到本节中定义的每个值(引用自 Microsoft),如下所示:

int version = BitConverter.ToUInt16(dataMashup.Take(FIELDS_LENGTH).ToArray(), 0);

int packagePartsLength = BitConverter.ToUInt16(dataMashup.Skip(FIELDS_LENGTH).Take(FIELDS_LENGTH).ToArray(), 0);
byte[] packageParts = dataMashup.Skip(FIELDS_LENGTH * 2).Take(packagePartsLength).ToArray();

int permissionsLength = BitConverter.ToUInt16(dataMashup.Skip(FIELDS_LENGTH  * 2 + packagePartsLength).Take(FIELDS_LENGTH).ToArray(), 0);
byte[] permissions = dataMashup.Skip(FIELDS_LENGTH * 3).Take(permissionsLength).ToArray();

int metadataLength = BitConverter.ToUInt16(dataMashup.Skip(FIELDS_LENGTH * 3 + packagePartsLength + permissionsLength).Take(FIELDS_LENGTH).ToArray(), 0);
byte[] metadata = dataMashup.Skip(FIELDS_LENGTH * 4 + packagePartsLength + permissionsLength).Take(metadataLength).ToArray();

int permissionsBindingLength = BitConverter.ToUInt16(dataMashup.Skip(FIELDS_LENGTH * 4 + packagePartsLength + permissionsLength + metadataLength).Take(FIELDS_LENGTH).ToArray(), 0);
byte[] permissionsBinding = dataMashup.Skip(FIELDS_LENGTH * 5 + packagePartsLength + permissionsLength + metadataLength).Take(permissionsBindingLength).ToArray();
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使用byte[]的包装部分,它代表一个Package从所述对象System.IO.Packaging的命名空间。

using (MemoryStream ms = new MemoryStream(packageParts)) {
    using (Package package = Package.Open(ms, FileMode.Open, FileAccess.ReadWrite)) {
        PackagePart section = package.GetParts().Where(x => x.Uri.OriginalString == "/Formulas/Section1.m").FirstOrDefault();

        string query;
        using (StreamReader reader = new StreamReader(section.GetStream())) {
            query = reader.ReadToEnd();
            // do other replacing, removing of query here
        }
        using (BinaryWriter writer = new BinaryWriter(section.GetStream())) {
            // write updated query back to package part
            writer.Write(Encoding.ASCII.GetBytes(query));
        }
    }

    packageParts = ms.ToArray();
}
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最后,我需要byte[]使用更新包中的新信息更新原始文件。

bytes = BitConverter.GetBytes(version)
            .Concat(BitConverter.GetBytes(packageParts.Length))
            .Concat(packageParts)
            .Concat(BitConverter.GetBytes(permissionsLength))
            .Concat(permissions)
            .Concat(BitConverter.GetBytes(metadataLength))
            .Concat(metadata)
            .Concat(BitConverter.GetBytes(permissionsBindingLength))
            .Concat(permissionsBinding);
doc.Root.Value = Convert.ToBase64String(bytes.ToArray());
entryStream.SetLength(0);
doc.Save(entryStream);
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以下是完整性的完整示例。它是一个控制台应用程序,它接收要更新的文件目录作为命令行参数,然后用新的服务器名称替换旧的服务器名称。

using System;
using System.Collections.Generic;
using System.Linq;
using System.IO;
using System.IO.Compression;
using System.Xml.Linq;
using System.IO.Packaging;
using System.Text;

namespace MyApp {
    class Program {
        private const int FIELDS_LENGTH = 4;

        static void Main(string[] args) {
            if (args.Length != 1) {
                Console.WriteLine("specify one directory to update");
            }
            if (!Directory.Exists(args[0])) {
                Console.WriteLine("directory does not exist");
            }

            IEnumerable<FileInfo> files = Directory.GetFiles(args[0]).Where(x => Path.GetExtension(x) == ".xlsx").Select(x => new FileInfo(x));

            foreach (FileInfo file in files) {
                using (FileStream fileStream = File.Open(file.FullName, FileMode.OpenOrCreate)) {
                    using (ZipArchive archive = new ZipArchive(fileStream, ZipArchiveMode.Update)) {

                        ZipArchiveEntry entry = archive.GetEntry("customXml/item1.xml");

                        IEnumerable<byte> bytes;
                        using (Stream entryStream = entry.Open()) {
                            XDocument doc = XDocument.Load(entryStream);

                            byte[] dataMashup = Convert.FromBase64String(doc.Root.Value);
                            int version = BitConverter.ToUInt16(dataMashup.Take(FIELDS_LENGTH).ToArray(), 0);

                            int packagePartsLength = BitConverter.ToUInt16(dataMashup.Skip(FIELDS_LENGTH).Take(FIELDS_LENGTH).ToArray(), 0);
                            byte[] packageParts = dataMashup.Skip(FIELDS_LENGTH * 2).Take(packagePartsLength).ToArray();

                            int permissionsLength = BitConverter.ToUInt16(dataMashup.Skip(FIELDS_LENGTH * 2 + packagePartsLength).Take(FIELDS_LENGTH).ToArray(), 0);
                            byte[] permissions = dataMashup.Skip(FIELDS_LENGTH * 3).Take(permissionsLength).ToArray();

                            int metadataLength = BitConverter.ToUInt16(dataMashup.Skip(FIELDS_LENGTH * 3 + packagePartsLength + permissionsLength).Take(FIELDS_LENGTH).ToArray(), 0);
                            byte[] metadata = dataMashup.Skip(FIELDS_LENGTH * 4 + packagePartsLength + permissionsLength).Take(metadataLength).ToArray();

                            int permissionsBindingLength = BitConverter.ToUInt16(dataMashup.Skip(FIELDS_LENGTH * 4 + packagePartsLength + permissionsLength + metadataLength).Take(FIELDS_LENGTH).ToArray(), 0);
                            byte[] permissionsBinding = dataMashup.Skip(FIELDS_LENGTH * 5 + packagePartsLength + permissionsLength + metadataLength).Take(permissionsBindingLength).ToArray();

                            // use double memory stream to solve issue as memory stream will change
                            // size when re-saving the data mashup object
                            using (MemoryStream packagePartsStream = new MemoryStream(packageParts)) {
                                using (MemoryStream ms = new MemoryStream()) {
                                    packagePartsStream.CopyTo(ms);
                                    using (Package package = Package.Open(ms, FileMode.Open, FileAccess.ReadWrite)) {
                                        PackagePart section = package.GetParts().Where(x => x.Uri.OriginalString == "/Formulas/Section1.m").FirstOrDefault();

                                        string query;
                                        using (StreamReader reader = new StreamReader(section.GetStream())) {
                                            query = reader.ReadToEnd();
                                            // do other replacing, removing of query here
                                            query = query.Replace("old-server", "new-server");
                                        }
                                        using (BinaryWriter writer = new BinaryWriter(section.GetStream())) {
                                            writer.Write(Encoding.ASCII.GetBytes(query));
                                        }
                                    }

                                    packageParts = ms.ToArray();
                                }

                                bytes = BitConverter.GetBytes(version)
                                            .Concat(BitConverter.GetBytes(packageParts.Length))
                                            .Concat(packageParts)
                                            .Concat(BitConverter.GetBytes(permissionsLength))
                                            .Concat(permissions)
                                            .Concat(BitConverter.GetBytes(metadataLength))
                                            .Concat(metadata)
                                            .Concat(BitConverter.GetBytes(permissionsBindingLength))
                                            .Concat(permissionsBinding);
                                doc.Root.Value = Convert.ToBase64String(bytes.ToArray());
                                entryStream.SetLength(0);
                                doc.Save(entryStream);
                            }
                        }
                    }
                }
            }
        }
    }
}
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注意:因为我只需要更新Package Parts部分,我可以确认这个解码/编码工作,但我没有测试Permissions, Metadata, 或的解码/编码Permissions Binding。如果你需要使用这些,这至少应该让你开始。

注意:此代码不会捕获错误或处理所有情况。它旨在作为如何更新 Power Query 文件中的连接的工作示例。随意根据需要调整它。