UPDATE customer.
if sy-subrc <> 0.
..... No entry with the customerno = 1, add error
handling
endif.
Updating multiple entries
Examlpe updating the field zchecked to 'X'
UPDATE zcostcheck set zchecked =
'X'
WHERE zcostcheck-zaar = zaar
and
zcostcheck-zmaaned = zmaaned and
zcostcheck-zbukrs = zbukrs and
zcostcheck-zsaknr = zsaknr2 and
zcostcheck-zgsber =
zgsber.