If you really want only one value - use a parameter. Otherwise
SELECT vbeln INTO TABLE dummy FROM vbak UP TO 2 ROWS WHERE vbeln IN sl_vbeln,
IF lines( dummy ) EQ 1.
" do logic
ENDIF.
If you really want only one value - use a parameter. Otherwise
SELECT vbeln INTO TABLE dummy FROM vbak UP TO 2 ROWS WHERE vbeln IN sl_vbeln,
IF lines( dummy ) EQ 1.
" do logic
ENDIF.