sql 多个字段分组,删除重复记录,保留ID最小的一条

IF OBJECT_ID('cardDetail') IS NOT NULL 
  DROP TABLE cardDetail
 CREATE TABLE cardDetail
 (
 id INT IDENTITY(1,1) PRIMARY KEY,
 cardNO VARCHAR(8),
 NAME VARCHAR(30),   
 idCard VARCHAR(18),
 cardState CHAR(1)--卡片状态 1正常 2注销
 )
  INSERT cardDetail(cardNO,NAME,idCard,cardState)
 VALUES
 ('001','张三','31010',1),
 ('005','张三','31010',1),
 ('002','李四','31011',1),
 ('003','王五','31012',1),
 ('006','张三','31010',0),
 ('004','王五','31012',1),
 ('007','欧阳','31013',1),
 ('008','欧阳','31013',1) 

--SQL编写要求 
 --根据idcard,cardstate分组后删除重复的,使其保留id最小的记录
 
 --最终结果为:
 (1,'001','张三','31010',1),
 (4,'003','王五','31012',1),
 (7,'007','欧阳','31013',1),

解决

with t as 
(
   select id,cardNO,NAME,idCard,cardState,
      row_number() over (partition by idcard,cardstate order by id) as od
   from cardDetail
)
select * from t where od = 1;
原文地址:https://www.cnblogs.com/yaunion/p/3954512.html