Java代码  
//把User表中相关字段的记录并入到UserAdditionalInfo表中  
insert tbl_user_additional_info  
(user_id,country,address,postal_code,phone,edu_background)  
select   
user_id,country,address,postal_code,phone,edu_background  
from tbl_user where user_id not in(select user_id from tbl_user_additional_info);  
  
//更改User表的结构  
alter table tbl_user   
drop user_id,  
drop country,  
drop address,  
drop postal_code,  
drop phone,  
drop edu_background;  
  
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