How to pipe Impala Data to CSV in PowerShell

The CData Cmdlets Module for Impala is a standard PowerShell module offering straightforward integration with Impala. Below, you will find examples of using our ApacheImpala Cmdlets with native PowerShell cmdlets.

Creating a Connection to Your Impala Data

In order to connect to Apache Impala, set the Server, Port, and ProtocolVersion. You may optionally specify a default Database. To connect using alternative methods, such as NOSASL, LDAP, or Kerberos, refer to the online Help documentation.

$conn = Connect-ApacheImpala  -Server "$Server" -Port "$Port"

Selecting Data

Follow the steps below to retrieve data from the Customers table and pipe the result into to a CSV file:

Select-ApacheImpala -Connection $conn -Table Customers | Select -Property * -ExcludeProperty Connection,Table,Columns | Export-Csv -Path c:\myCustomersData.csv -NoTypeInformation

You will notice that we piped the results from Select-ApacheImpala into a Select-Object cmdlet and excluded some properties before piping them into an Export-Csv cmdlet. We do this because the CData Cmdlets append Connection, Table, and Columns information onto each "row" in the result set, and we do not necessarily want that information in our CSV file.

Deleting Data

The following line deletes any records that match the criteria:

Select-ApacheImpala -Connection $conn -Table Customers -Where "Country = US" | Remove-ApacheImpala

Inserting and Updating Data

The cmdlets make data transformation easy as well as data cleansing. The following example loads data from a CSV file into Impala, checking first whether a record already exists and needs to be updated instead of inserted.

Import-Csv -Path C:\MyCustomersUpdates.csv | %{
  $record = Select-ApacheImpala -Connection $ApacheImpala -Table Customers -Where ("Id = `'"+$_.Id+"`'")
  if($record){
    Update-ApacheImpala -Connection $apacheimpala -Table Customers -Columns ("City","CompanyName") -Values ($_.City, $_.CompanyName) -Where ("Id = `'"+$_.Id+"`'")
  }else{
    Add-ApacheImpala -Connection $apacheimpala -Table Customers -Columns ("City","CompanyName") -Values ($_.City, $_.CompanyName)
  }
}

As always, our goal is to simplify the way you connect to data. With cmdlets users can install a data module, set the connection properties, and start building. Download Cmdlets and start working with your data in PowerShell today!