execute_action with mass CONFIRM in gateway

Hello,

I am trying to implement mass creation of so order in gateway.

can you anyone provide me some snippets code on this?

I have defined in model

  lo_action = model->create_action( 'CONFIRM' ).

   lo_action->set_return_entity_set( 'SOHdr' ).

   lo_action->set_http_method( 'POST' ).

   lo_action->set_return_multiplicity( '1').   " what should we put here ??

   lo_parameter = lo_action->create_input_parameter( iv_parameter_name = 'WiId'

                                                     iv_abap_fieldname = 'WI_ID' ).

   lo_parameter->/IWBEP/IF_MGW_ODATA_PROPERTY~set_type_edm_string( ).  "What should we put here ?

can we define the type of parameter as a range of a table?

Thank you.

Benjamin