SQL Update from One Table to Another Based on a ID Match

MS Sql

UPDATE c4 SET Price=cp.Price*p.FactorRate FROM TableNamea_A c4
inner join TableNamea_B p on c4.Calcid=p.calcid
inner join TableNamea_A cp on c4.Calcid=cp.calcid
WHERE c4..Name='MyName';

Oracle 11g

MERGE INTO TableNamea_A u
using
(
SELECT c4.TableName_A_ID,(cp.Price*p.FactorRate) as CalcTot
FROM TableNamea_A c4
inner join TableNamea_B p on c4.Calcid=p.calcid
inner join TableNamea_A cp on c4.Calcid=cp.calcid
WHERE p.Name='MyName'
) rt
on (u.TableNamea_A_ID=rt.TableNamea_B_ID)
WHEN MATCHED THEN
Update set Price=CalcTot ;