一、
select distinct address from people where bmname0='樊城区' and bmname='中原派出所' and addrc=''
distinct作用：过滤掉 address 字段中，多余的重复记录，只保留一条（只能过滤一个字段）
二、
Update people set addrc=@addrc,addrz=@addrz Where bmname0='襄城区' and bmname='王府派出所' and addrc='' and address in ('东街二十三号','檀溪西路43号')
in作用：判断给定的值是否在子查询的集合里
三、
Update people set addrc=@addrc,addrz=@addrz Where bmname0='襄城区' and bmname='王府派出所' and addrc='' and address
in (select distinct address from people where bmname0='樊城区' and bmname='中原派出所' and addrc='')