将PSCustomObject与对象进行比较

Question

我创建了一个PsCustomObject，当调用变量为ISE时，它会读取相关数据的表。但是，如果我尝试将PsCustomObject与另一个对象进行比较，PsCustomObject无法正确读取。我想告诉脚本，如果现有CSV中的任何行与PSCustomObject匹配，则不会将数据导出到CSV，换句话说，跳过CSV文件中的重复行。CSV可能有也可能没有多行。

$fileInfo = @(
                        [pscustomobject]@{
                            user_id = $user
                            studio = $studio
                            function = $Task
                            end_time_local = $creationTime
                            asin = $ASIN
                            variant = $variant
                            process_class_id = $processClass
                            }
                           )
$currentData = Import-Csv "$scansFolder\$fileName.csv"
if($fileInfo -ne $currentData){
$fileInfo | Export-Csv "$scansFolder\$fileName.csv" -Append -NoTypeInformation -Force
}

Answer 1

[pscustomject]是一个。NET引用类型，因此将两个实例^[1]与-eq进行比较将测试引用相等性（标识），即如果两个实例是一个相同的对象^[2]-在您的场景中显然不是这种情况。

假设您的自定义对象的属性是值类型或字符串的实例（看起来是这样），您可以使用Compare-Object按对象的属性值比较对象，并能够比较两个集合：

$fileInfo = @(
  [pscustomobject]@{
      user_id = $user
      studio = $studio
      function = $Task
      end_time_local = $creationTime
      asin = $ASIN
      variant = $variant
      process_class_id = $processClass
      }
)

# Get the property names.
# This assumes that the CSV data has (at least) the same
# set of properties (columns).
$propNames = $fileInfo[0].psobject.properties.Name

$currentData = Import-Csv "$scansFolder\$fileName.csv"

# Compare the $fileInfo custom object(s) to the custom objects read
# from the CSV file and only export those that are unique to the RHS ('=>')
# back to the file, i.e., those that don't match $fileInfo.
Compare-Object -Property $propNames $fileInfo $currentData |
  Where-Object SideIndicator -eq '=>' | Select-Object InputObject | 
    Export-Csv "$scansFolder\$fileName.csv" -Append -NoTypeInformation -Force

导入Csv，输出pscustomobject实例

参见等式比较帮助主题（为C编写，但类似于PowerShell的eq操作符）