问大家关于一个多表更新的事务问题

if not exists(select top 1 * from uSignin where uid='{0}' and cid='{1}' and DATEDIFF(MINUTE,sdate,getdate())=0) begin insert into uSignin(uid,cid,sdate,sremark,stype) values('{0}','{1}',getdate(),'','{3}'); update [contract] set lastcount=lastcount-1 where cid={1}; update [dUser] set point=point+2 where uid={0}; insert into pointlog(uid,rinfo,getpoint) values('{0}','{2}','10') end

我有多条sql语句，在程序中合并成了一条去执行，这样还需要用事务吗？