oracle 中的事务和update from 语句

begin 

savepoint aaa;

update ZDCOLUMNVALUE

set ZDCOLUMNVALUE.TEXTVALUE=(

select substr(content,instr(CONTENT,'src="/zcms/wwwroot/DWRCB/upload/logo/',1,1)+25,30)

from ZCARTICLE where ZCARTICLE.SITEID=239 and ZCARTICLE.CATALOGID=9502 and ZCARTICLE.content like '%src="/zcms/wwwroot/DWRCB/upload/logo%'

and ZCARTICLE.id=ZDCOLUMNVALUE.RELAID

)

where ZDCOLUMNVALUE.RELAID in (

select id

from ZCARTICLE where SITEID=239 and CATALOGID=9502 and content like '%src="/zcms/wwwroot/DWRCB/upload/logo%'

);

rollback to savepoint aaa;

end ;