如何删除包括第一行在内的重复行？

Question

我有一个 table 列

Car   |   User  |  Location  |  Time  |  Type

我想删除所有重复的行，仅保留基于 car, user, location, time 列的不同行

例如：

Car   |   User  |  Location  |         Time          |  Type
-----------------------------------------------------------------
  1   |    Ben  |   Chicago  |  2022-02-12 03:12:45  |   OUT        //should be deleted
-----------------------------------------------------------------
  1   |    Ben  |   Chicago  |  2022-02-12 03:12:45  |   IN         //should be deleted
-----------------------------------------------------------------
  2   |    Sam  |  New York  |  2022-02-12 04:42:45  |   OUT        //should be kept
-----------------------------------------------------------------
  1   |    Ben  |   Chicago  |  2022-02-12 04:50:00  |   OUT        //should be kept

为了更容易获得帮助

CREATE TABLE rent_logs (
  car varchar(30),
  user varchar(30),
  location varchar(30),
  time datetime,
  type varchar(10)
);

INSERT INTO rent_logs ( car, user, location, time, type ) 
VALUES ( 1, 'Ben', 'Chicago','2022-02-12 03:12:45',  'OUT' ), 
( 1, 'Ben', 'Chicago',' 2022-02-12 03:12:45',  'IN' ), 
( 2, 'Sam', 'New york','2022-02-12 04:42:45',  'OUT' ), 
( 1, 'Ben', 'Chicago','2022-02-12 04:50:00',  'OUT' ), 
( 2, 'Sam', 'New york','2022-02-12 07:32:12 ',  'IN' ), 
( 1, 'Ben', 'Chicago','22022-02-12 08:18:45',  'IN' ), 
( 3, 'Mia', 'Chicago','2022-02-12 09:12:43',  'OUT' ), 
( 1, 'Ben', 'Chicago','2022-02-12 09:27:23',  'IN' )

Answer 1

将 table 加入一个查询，该查询在 rent_logs 和 returns 中聚合所有具有重复的行：

DELETE r
FROM rent_logs r
INNER JOIN (
  SELECT car, user, location, time
  FROM rent_logs
  GROUP BY car, user, location, time
  HAVING COUNT(*) > 1
) t ON (t.car, t.user, t.location, t.time) = (r.car, r.user, r.location, r.time);

参见demo。

如何删除包括第一行在内的重复行？

How to delete duplicate rows including the first row as well?

mysql

sql

database

join

sql-delete