Select-Object of multiple properties - powershell

Question

I am trying to find an elegant way to put the metadata of a table of type System.Data.DataTable into a multi-dimensional array for easy reference in my program. My approach to the issue so far seems tedious.
Assuming $DataTable being the DataTable in question
What I tried to do so far was:
$Types = $DataTable.Columns | Select-Object -Property DataType
$Columns= $DataTable.Columns | Select-Object -Property ColumnName
$Index = $DataTable.Columns | Select-Object -Property ordinal
$AllowNull = $DataTable.Columns | Select-Object -Property AllowDbNull
Then painfully going through each array, pick up individual items and put them in my multi-dimensional array $TableMetaData.
I read in the documentation of Select-Object and it seems to me that only 1 property can be selected at 1 time? I think I should be able to do all the above more elegantly and store the information in $TableMetaData.
Is there a way to easily pick up multiple properties and put them in a multi-dimensional array in 1 swoop?

Answer 1

I read the documentation of Select-Object and it seems to me that only 1 property can be selected at 1 time?
This is not true, Select-Object can take any number of arguments to the -Property parameter
$ColumnInfo = $DataTable.Columns | Select-Object -Property DataType,ColumnName,ordinal,AllowDbNull
Now $ColumnInfo will contain one object for each column, having all 4 properties.
Rather than using a multi-dimensional array, you should consider using a hashtable (#{}, an unordered dictionary):
$ColumnInfo = $DataTable.Columns | ForEach-Object -Begin { $ht = #{} } -Process {
$ht[$_.ColumnName] = $_
} -End { return $ht }
Here, we create an empty hashtable $ht (the -Begin block runs just once), then store each column object in $ht using the ColumnName as the key, and finally return $ht, storing it in $ColumnInfo.
Now you can reference metadata about each column by Name:
$ColumnInfo.Column2
# or
$ColumnInfo["Column2"]

Answer 2

One easy way to do this is to create an "empty" variable with Select-Object. Here is a sample command:
$DataTableReport = "" | Select-Object -Property DataType, ColumnName, ordinal, AllowDbNull
Then, link the $DataTableReport to the $Types, $Columns, $Index, and the $AllowNull properties as shown below:
$DataTableReport.Types = $DataTable.DataType
$DataTableReport.Columns = $DataTable.ColumnName
$DataTableReport.Index = $DataTable.ordinal
$DataTableReport.AllowNull = $DataTable.AllowDbNull
Finally, call the DataTableReport variable.
$DataTableReport # will display all the results in a tabular form.