mysql update select

update ey_dq_copy a inner join (select b.cityid,b.xian from ey_dq_copy b) c set a.city = c.cityid WHERE a.area = c.xian and prov = city and city = xian;
update
ey_dq_copy a inner join (select b.cityid,b.xian from ey_dq_copy b) c set a.city = c.cityid WHERE a.pov = c.xian and city = xian;

update
ey_dq_copy a inner join (select b.cityid,b.xian from ey_dq_copy b) c set a.city = c.cityid WHERE a.city = c.xian and pid <> 0;