Smartobject method

1.  Are you attempting to perform this execution before the Smartobject layer?  If so, perhaps exposing a stored procedure via the SQL server service broker:

http://help.k2.com/onlinehelp/k2blackpearl/userguide/current/webframe.html#stored_procedures.html

http://help.k2.com/kb001451

2.a.  Or if inside a process a Smartobject Event call with input/filter:

https://help.k2.com/onlinehelp/k2blackpearl/userguide/current/webframe.html#SMOW01.html

2.b. Or SmartObject Integration within a K2 Events where you can 'determine how the results should be returned.' (All/Single)

https://help.k2.com/onlinehelp/k2blackpearl/userguide/current/webframe.html#SmartObject%20Integration%20with%20K2%20Events.html