来帮我看看这句UPDATE语句
UPDATE t1 SET a=t2.a,b=t2.b,c=t2.cfrom table1 t1inner join table2 t2 on t1.id=t2.reqid
update table1 set a = table2.a, b = table2.b, c = table2.cfrom table2where table2.reqid= table1.id