powershell get-swisdata multiple parameters

Running SDK 2.0 and working in powershell.

Trying to running a query with multiple parameters and I'm running into errors. Tried looking for documentation but not finding anything even in the examples

this is my query:

$checkmembership = Get-SwisData $swis "select ContainerID,MemberPrimaryId,MemberURI from orion.containermembers where memberuri=@a AND ContainerID=@b" @{a=$getnodeuri; b=$getcontainerid;}

and this is what I get:

Get-SwisData : Must declare the scalar variable "@b".

At line:1 char:20

+ $checkmembership = Get-SwisData $swis "select ContainerID,MemberPrimaryId,Member ...

+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    + CategoryInfo          : InvalidOperation: (:) [Get-SwisData], FaultException`1

    + FullyQualifiedErrorId : SwisError,SwisPowerShell.GetSwisData

Am I missing something?