NEWBIE - Update SQL based on Sub-query

[enbw]

I have an sql select query.

select distinct pub.partopr.partnum, pub.partmtl.revisionnum, pub.partmtl.mtlpartnum, pub.partmtl.qtyper, pub.partopr.prodstandard
from pub.partmtl, pub.partopr
where
pub.partmtl.mtlpartnum like '%MELT%' and
pub.partmtl.partnum = pub.partopr.partnum
and pub.partmtl.revisionnum = pub.partopr.revisionnum
and pub.partmtl.relatedoperation = pub.partopr.oprseq
and pub.partmtl.qtyper <> pub.partopr.prodstandard * 100

I want to know if I can use this in a UPDATE query. I want to update prodstandard by qtyper / 100. I have tried it but I can't seem to query it.

Thanks