Powershell - 从 HTML 表中导出列值

Question

I'm using the following Powershell script that calls an API that returns an HTML table.我正在使用以下 Powershell 脚本调用返回 HTML 表的 API。 I need to convert the column of data with the header 'DBName' to an array that I can use later in the script.我需要将带有标题“DBName”的数据列转换为稍后可以在脚本中使用的数组。

I have tried using the following and nothing seems to work.我尝试使用以下方法，但似乎没有任何效果。

$req = Invoke-WebRequest $url
$table = $req.ParsedHtml.getElementsByTagName('table')

Here is the Powershell script I am using to call the API and then set the results to the variable "$DBList"这是我用来调用 API 的 Powershell 脚本，然后将结果设置为变量“$DBList”

$SomeServer = 'databaseserver.domain.com,1433'

$PsCredential = New-Object System.Management.Automation.PSCredential -ArgumentList ($username, $password)

$API_CALL = @{
Method = "GET"
URI    = "HTTPS://software.domain.com:111/TEST1/DATA/Stuff?Target=$SomeServer&Query_Name=sys_databases&Technology=SQLServer"
Credential = $PsCredential
}

#Get the webpage
$HTML = Invoke-RestMethod @API_CALL -verbose 

<#

Something converts the HTML table to a PS object that I can extract the database names

#>


$DBList = $HTML | Select-Object -Property name | Where-Object name -NotMatch "master|model|msdb|tempdb" | Sort-Object -Property name

In Powershell, if you select $HTML, this is what is generated when I call the API:在Powershell中，如果你选择$HTML，这是我调用API时生成的：

 <!DOCTYPE html> <html> <head> <link rel="icon" href="data:,"> <meta name="google" content="notranslate"> </head> <title>"Results</title> <meta name="viewport" content="width=device-width, initial-scale=1"> <style> /* W3.CSS 4.13 June 2019 by Jan Egil and Borge Refsnes */ html{box-sizing:border-box}*,*:before,*:after{box-sizing:inherit} /* Extract from normalize.css by Nicolas Gallagher and Jonathan Neal git.io/normalize */ .w3-table,.w3-table-all{border-collapse:collapse;border-spacing:0;width:100%;display:table}.w3-table-all{border:1px solid #ccc} .w3-bordered tr,.w3-table-all tr{border-bottom:1px solid #ddd}.w3-striped tbody tr:nth-child(even){background-color:#f1f1f1} .w3-table-all tr:nth-child(odd){background-color:#fff}.w3-table-all tr:nth-child(even){background-color:#f1f1f1} .w3-hoverable tbody tr:hover,.w3-ul.w3-hoverable li:hover{background-color:#ccc}.w3-centered tr th,.w3-centered tr td{text-align:center} .w3-table td,.w3-table th,.w3-table-all td,.w3-table-all th{padding:8px 8px;display:table-cell;text-align:left;vertical-align:top} .w3-table th:first-child,.w3-table td:first-child,.w3-table-all th:first-child,.w3-table-all td:first-child{padding-left:16px} .container2 { position: relative; width: 99%; height: 100%; overflow: hidden; padding-top: 37%; /* 16:9 Aspect Ratio */ } .responsive-iframe2 { position: absolute; top: 1%; left: 0; bottom: 0; right: 0; width: 99.5%; height: 98%; border: none; } </style> <body> <div style="overflow-x:auto;"> <table class="w3-table-all w3-hoverable"> <thead> <tr class="w3-light-grey"> <th>collation_name</th> <th>compatibility_level</th> <th>ConnectionString</th> <th>DBname</th> </tr> </thead> <tr> <td>SQL_Latin1_General_CP1_CI_AS</td> <td>140</td> <td>server.domain.com,1433</td> <td>Database_1</td> </tr> <tr> <td>SQL_Latin1_General_CP1_CI_AS</td> <td>140</td> <td>server.domain.com,1433</td> <td>Database_2</td> </tr> <tr> <td>SQL_Latin1_General_CP1_CI_AS</td> <td>140</td> <td>server.domain.com,1433</td> <td>Database_3</td> </tr> </table> </div> <p></p> </body> </html>

At the end, I would like for the variable $DBList to show: Database_1 Database_2 Database_3最后，我希望变量 $DBList 显示：Database_1 Database_2 Database_3

Answer 1

It seems that all parsing done in Invoke-WebRequest somehow depends on Internet Explorer.在Invoke-WebRequest完成的所有解析似乎都以某种方式依赖于 Internet Explorer。 I think we all agree that was a bad idea, and I am not surprised it's broken (doesn't work for me either, don't ask me why ... there are already other posts about this.)我想我们都同意这是一个坏主意，我对它坏了并不感到惊讶（对我也不起作用，不要问我为什么……已经有其他帖子了。）

The best way is probably to use some HTML-parsing library.最好的方法可能是使用一些 HTML 解析库。 I like HTML Agility Pack .我喜欢HTML Agility Pack 。

However, I was able to create an all .NET/PowerShell version based on this post that uses the Windows Forms WebBrowser :但是，我能够基于这篇使用 Windows Forms WebBrowser 的帖子创建一个全 .NET/PowerShell 版本：

$HTML = Invoke-RestMethod @API_CALL -Verbose 
Add-Type -AssemblyName System.Windows.Forms
$wb = New-Object System.Windows.Forms.WebBrowser
$wb.ScriptErrorsSuppressed = $true
$wb.DocumentText = ""
$doc = $wb.Document.OpenNew($true)
$doc.Write($HTML)
($DBList = $doc.GetElementsByTagName("table").GetElementsByTagName("tr") | foreach {
    $_.GetElementsByTagName("td") | select -First 1 -Skip 3 -ExpandProperty InnerText
})

Answer 2

There are a few ConvertFrom-HtmlTable , Get-HtmlTable , etc. cmdlets around but found them somewhat limited with regards to case insensitive HTML tags and embedded table tags (as in your case: a <tr> tag in a <thead> tag).有一些ConvertFrom-HtmlTable 、 Get-HtmlTable等 cmdlet，但发现它们在不区分大小写的 HTML 标记和嵌入的表格标记方面有些受限（如您的情况： <thead>标记中的<tr> <thead>标记） .
Therefore, I decided to created my own Read-HtmlTable :因此，我决定创建自己的Read-HtmlTable ：

Function Read-HtmlTable {
    [CmdletBinding()][OutputType([Object[]])] param(
        [Parameter(ValueFromPipeLine = $True, Mandatory = $True)][String]$html
    )
    Begin {
        Function Get-TopElements { # Get elements by (insensitive) name that do not have a (grand)parent with the same name
            [CmdletBinding()][OutputType([Xml.XmlElement[]])] param(
                [Parameter(Mandatory = $True)][String]$Name,
                [Parameter(Mandatory = $True, ValueFromPipeLine = $True)][Xml.XmlElement]$Element
            )
            if ($Element.Name -eq $Name) { $Element }
            else { $Element.SelectNodes('*') | Foreach-Object { $_ | Get-TopElements $Name } } 
        }
    }
    Process {
        $body = ([Xml]($html -Replace '^[\s\S]*(?=\<body\>)' -Replace '(?<=\<\/body\>)[\s\S]*$')).body
        foreach($table in ($body | Get-TopElements 'table')) {
            $Names = $Null
            foreach ($tr in ($table | Get-TopElements 'tr')) {
                if (!$Names) { $Names = ($tr | Get-TopElements 'th').'#text' }
                if (!$Names) { $Names = ($tr | Get-TopElements 'td').'#text' }
                else {
                    $Values = ($tr | Get-TopElements 'td').'#text'
                    $Properties = @{}; $i = 0
                    Foreach ($Value in $Values) { $Properties[$Names[$i++]] = $Value }
                    [pscustomobject]$Properties
                }
            }
        }
    }
}

$HTML | Read-HtmlTable

collation_name               compatibility_level DBname     ConnectionString
--------------               ------------------- ------     ----------------
SQL_Latin1_General_CP1_CI_AS 140                 Database_1 server.domain.com,1433
SQL_Latin1_General_CP1_CI_AS 140                 Database_2 server.domain.com,1433
SQL_Latin1_General_CP1_CI_AS 140                 Database_3 server.domain.com,1433

Powershell - 从 HTML 表中导出列值

问题描述

2 个解决方案

解决方案1
0 2020-11-06 11:22:39

解决方案2
0 2020-11-07 14:56:48

Powershell - 从 HTML 表中导出列值

问题描述

2 个解决方案

解决方案1 0 2020-11-06 11:22:39

解决方案2 0 2020-11-07 14:56:48

解决方案1
0 2020-11-06 11:22:39

解决方案2
0 2020-11-07 14:56:48