Select not working after db-migration

Hi experts,

I've a question.

We made a database migration from Oracle to Sybase ASE.

And now I think, that the coding below is not working anymore.

I've I check the tables and entries directly via se16 I should get an result - like in the past.

But in the program the statement don't delivers any result.

May it be, that the syntax has to be changed for Sybase ASE????

Thank you

btw:  header_guid is filled with a correct guid

  select single b~partner_guid
    from crmv_linkpartner as a
    inner join but000 as b
    on a~partner_no eq b~partner_guid
    into lv_bupa_guid
    where a~guid_hi eq header_guid
      and a~partner_fct eq 'SLFN0002'
      and a~mainpartner eq 'X'.

  IF sy-subrc EQ 0.