ORACLE中将一个值赋值到另一个表的值
update tmp_customer_list t
set email = (select email from tmp_etl_customerlist e where t.mobile = e.mobile);
更加高效的方法：
merge into customer_list t
using CUSTOMER_LIST_TMP01 t1
on(t.customerkey = t1.customerkey)
when matched then update set t.customerlevel = t1.customerlevel ;
commit;