如何在 powershell 中读取 mongodb 5.0 集合

Question

我正在尝试使用带有以下代码的 powershell 读取 mongodb5.0 中集合的文档。

我在最后一行遇到错误 $collection.find($query)

方法调用失败，因为 [MongoDB.Driver.MongoCollectionImpl`1[[System.Management.Automation.PSObject, System.Management.Automation, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]]] 不包含名为 'Find'.

function Get-MongoDBCollection {
Param(
    $database,
    $CollectionName,
    $settings = $null, #[MongoDB.Driver.MongoCollectionSetting]
    $returnType = [PSOBJECT]
)
    $method = $database.GetType().GetMethod('GetCollection')
    $GenericMethod = $method.MakeGenericMethod($returnType)
    $GenericMethod.Invoke($database,[object[]]($CollectionName,$settings))
}

$mongoDbDriverPath = 'C:\Users\testuser\'
$mongoServer = 'localhost:27017'

Add-Type -Path "$($mongoDbDriverPath)MongoDB.Bson.dll"
Add-Type -Path "$($mongoDbDriverPath)MongoDB.Driver.dll"

add-type -path "$mongoDbDriverPath\System.Runtime.InteropServices.RuntimeInformation.dll"
Add-Type -Path "$mongoDbDriverPath\MongoDB.Bson.dll"
Add-Type -Path "$mongoDbDriverPath\MongoDB.Driver.dll"
add-type -path "$mongoDbDriverPath\DnsClient.dll";
#Add-Type -path "$mongoDbDriverPath\MongoDb.Driver.Core.dll"    
Add-Type -Path "$mongoDbDriverPath\MongoDB.Libmongocrypt.dll"
Add-Type -Path "$mongoDbDriverPath\System.ValueTuple.dll"

$databaseName = 'myDatabase'
$collectionName = 'myCollection'

$client = New-Object -TypeName MongoDB.Driver.MongoClient -ArgumentList "mongodb://$mongoServer"
$database = $client.GetDatabase($databaseName)

$Collection = Get-MongoDBCollection $database $collectionName
#$Collection = Get-MongoDBCollection $database $collectionName -returnType  ([MongoDB.Bson.BsonDocument])

$query = new-object MongoDB.Bson.BsonDocument('Name','john')

$collection.find($query)

Answer 1

Find 是一种扩展方法，与 C# 编译器不同，PowerShell 无法弄清楚如何解决这些问题。您必须引用定义扩展方法的底层静态类型才能调用它：

[MongoDb.Driver.IMongoCollectionExtensions]::Find($collection, $query)

但是由于 Find 也是通用的，我们需要使用 MakeGenericType() 的等效方法来创建我们可以调用的特定于类型的版本：

function Find-MongoDbDocument
{
  param(
    [Parameter(Mandatory = $true, Position = 0)]
    [MongoDB.Driver.IMongoCollection[MongoDB.Bson.BsonDocument]]
    $collection,

    [Parameter(Position = 1)]
    [MongoDB.Driver.FilterDefinition[MongoDB.Bson.BsonDocument]]$filter = $null,

    [ValidateRange(1,100000)]
    [int]$Limit
  )

  $documentType = [MongoDB.Bson.BsonDocument]

  # Discover the relevant Find() extension method overload
  $findDefinition = [MongoDB.Driver.IMongoCollectionExtensions].GetMethods() |Where-Object {$_.Name -eq 'Find' -and $_.GetParameters().Count -eq 3} |Select-Object -First 1

  # Make a type-parameter-specific version of Find() 
  $findBsonMethod = $findDefinition.MakeGenericMethod($documentType)

  # Invoke Find()
  $result = $findBsonMethod.Invoke($null, @($collection, $filter, $null))

  # Limit the result set size, if requested
  if($PSBoundParameters.ContainsKey('Limit')){
    $result = $result.Limit($Limit)
  }

  # Fetch the results
  $cursor = $result.ToCursor()
  while($cursor.MoveNext([System.Threading.CancellationToken]::None)){
    Write-Output $cursor.Current 
  }
}

注意我使用 [BsonDocument] 而不是 [psobject] 作为文档类型 - MongoDB 驱动程序已经原生支持反序列化为 [BsonDocument]（但不是 [psobject]）。

这样使用：

# Obtain collection object 
$collection = Get-MongoDBCollection $database $collectionName -returnType $([MongoDB.Bson.BsonDocument])

# Define filter
$filter = [MongoDB.Bson.BsonDocument]::new('Name', 'John')

# Fetch first 100 matching documents
Find-MongoDbDocument -Collection $collection -Filter $filter -Limit 100

如何在 powershell 中读取 mongodb 5.0 集合

How to read mongodb 5.0 collections in powershell

c#

collections

powershell

mongodb