why is no data being returned in my PowerShell script - oracle

Question

add-type -AssemblyName System.Data.OracleClient
$username = "SYSTEM"
$password = "password"
$data_source = "production"
$connection_string = "User Id=$username;Password=$password;Data Source=$data_source"
try{
$statement = "SELECT SYSDATE FROM DUAL"
$con = New-Object System.Data.OracleClient.OracleConnection($connection_string)
$con.Open()
$cmd = $con.CreateCommand()
$cmd.CommandText = $statement
$result = $cmd.ExecuteReader()
# Do something with the results...
Write-Host $result + "data"
If($result.HasRows) {
try {
while ($result.Read())
{
"[0] : " + $result.GetValue(0)
}
}
catch
{
#log error
}
finally
{
$con.Close()
}
}
} catch {
Write-Error (“Database Exception: {0}`n{1}” -f `
$con.ConnectionString, $_.Exception.ToString())
} finally{
if ($con.State -eq ‘Open’) { $con.close() }
}
I am executing SELECT SYSDATE FROM DUAL
I am expecting 21-MAY-19
However no data is returned. (no error is presented either)

Answer 1

As mentioned in the above comments, you've to send the content of $result to PowerShells output stream. The output stream is used to realize the pipeline feature of Powershell. If you wrap your code in e.g. "myCode.ps1" and invoke it via:
.\myCode.ps1
The content of $result is pushed in the output stream (pipeline). Since no other cmdlet is attached to the call of myCode.ps1 the Powershell host (= your command line) will receive the content. The default behavior of the host is to dump the content.
So add the following to your code:
$result = $cmd.ExecuteReader()
# Return $result to the pipeline
$result
Read more about pipelines here and more about streams here.
UPDATE1: This link describes more or less the code sample of the question. Maybe the Orcale .NET data provider is missing. Add it via:
Add-Type -Path "PathToDll\Oracle.ManagedDataAccess.dll"
Hope that helps.