如何在csv中的哈希表中为一个键具有多个值 [英] How to have multiple values for one key in hashtable from csv

问题描述

我试图创建一个空的哈希表，导入CSV，按ID将事物分组，然后将每个组添加到哈希表中。

I tried to create an empty hashtable, import your CSV, group things by ID, then add each group to the hashtable.

但是由于某些原因，我遇到了错误：

But for some reason I am getting error:

Exception calling "Add" with "2" argument(s): "Key cannot be null.
Parameter name: key"
At line:4 char:5
+     $myHT.add($_.Name,$_.Group.Name)
+     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : ArgumentNullException

我有然后尝试以下更接近我期望的输出的内容：

I have then tried the following which is much closer to my desired output:

$myCSV = Import-Csv "X:\Path\To\My\CSV\File.csv"
$myCSV | Group-Object -Property ID | Select-Object -Property @{N="ID";E={$_.Name}},@{N="Name";E={$_.Group.Name -join ","}}

但是，如果我在csv中具有相同的名称和相同的ID，是否仍然存在重复项。无论如何，只有唯一的名称吗？
我目前得到以下信息：

However, if I still have duplicates if I have the same name with the same ID in my csv. Is there anyway to get unique names only? I currently get the following:

ID    Name
1234  John, John, Jeff
1235  Jane
1236  Bob

我只希望名称已经存在一次。

I only want the name to be added once if it already exists.

推荐答案

如果您想要一个哈希表，那么最简单的方法是制作一个空表，导入CSV并进行分组按ID，然后将每个组添加到哈希表。

If you want a hashtable, then the easiest way would be to make an empty one, import your CSV, group things by ID, then add each group to the hashtable.

$myHT = @{}
$myCSV = Import-Csv "X:\Path\To\My\CSV\File.csv"
$myCSV | Group ID | ForEach-Object {
    $myHT.add($_.Name,$_.Group.Name)
}

这不会在名称之间放置漂亮的'，'，但是哈希表中的每个键的值都是名称数组。

That won't put a pretty ', ' between names, but each key in the hashtable will have a value that's an array of names.

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