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https://blog.csdn.net/javajxz008/article/details/53493509
第一步：
select *,row_number() over(distribute by custno sort by recdate asc,appid asc,case when product=cardtype then '1' else '2' end asc) as rank from tbl_custinfo where pt='20161015'
第二步：
select * from
(select *,row_number() over(distribute by custno sort by recdate asc,appid asc,case when product=cardtype then '1' else '2' end asc) as rank from tbl_custinfo where pt='20161015') a
where a.rank=1;