问题
I have the following query that I want to return all the duplicated rows to the user for them to decide which one to use:
SELECT * FROM `table`
INNER JOIN (SELECT * FROM table GROUP BY barcode HAVING (COUNT(id) > 1)) dup
ON `table`.`column` = `dup`.`column`
Each part of this query appears to return the correct response but when adding the 2 together I am getting duplicates of the duplicates if that makes sense. Any ideas on what is going on?
My table data
+----+------------------------+---------------------+---------------------+
| id | barcode | created_at | updated_at |
+----+------------------------+---------------------+---------------------+
| 2 | 0000000002800000008741 | 2015-10-05 12:04:52 | 2015-10-05 12:04:52 |
| 3 | 0000000002800000008738 | 2015-10-05 13:15:02 | 2015-10-05 13:37:51 |
| 4 | 0000000002800000008741 | 2015-10-05 13:22:38 | 2015-10-05 13:22:38 |
| 5 | 0000000002800000008738 | 2015-10-05 13:22:38 | 2015-10-05 13:22:38 |
| 6 | 0000000002800000008738 | 2015-10-05 13:23:29 | 2015-10-05 13:23:29 |
| 7 | 0000000002800000008738 | 2015-10-05 13:24:49 | 2015-10-05 13:24:49 |
| 8 | 0000000002800000008741 | 2015-10-05 13:24:49 | 2015-10-05 13:24:49 |
| 9 | 0000000002800000008738 | 2015-10-05 13:37:51 | 2015-10-05 13:37:51 |
| 10 | 0000000002800000008741 | 2015-10-05 13:37:51 | 2015-10-05 13:37:51 |
+----+------------------------+---------------------+---------------------+
The output of the above query
+----+------------------------+---------------------+---------------------+
| id | barcode | created_at | updated_at |
+----+------------------------+---------------------+---------------------+
| 2 | 0000000002800000008741 | 2015-10-05 12:04:52 | 2015-10-05 12:04:52 |
| 3 | 0000000002800000008738 | 2015-10-05 13:15:02 | 2015-10-05 13:37:51 |
| 4 | 0000000002800000008741 | 2015-10-05 13:22:38 | 2015-10-05 13:22:38 |
| 5 | 0000000002800000008738 | 2015-10-05 13:22:38 | 2015-10-05 13:22:38 |
| 6 | 0000000002800000008738 | 2015-10-05 13:23:29 | 2015-10-05 13:23:29 |
| 7 | 0000000002800000008738 | 2015-10-05 13:24:49 | 2015-10-05 13:24:49 |
| 8 | 0000000002800000008741 | 2015-10-05 13:24:49 | 2015-10-05 13:24:49 |
| 9 | 0000000002800000008738 | 2015-10-05 13:37:51 | 2015-10-05 13:37:51 |
| 10 | 0000000002800000008741 | 2015-10-05 13:37:51 | 2015-10-05 13:37:51 |
| 11 | 0000000002800000008738 | 2015-10-05 13:39:05 | 2015-10-05 13:39:05 |
| 12 | 0000000002800000008741 | 2015-10-05 16:16:41 | 2015-10-05 16:16:41 |
| 13 | 0000000002800000008738 | 2015-10-05 16:39:56 | 2015-10-05 16:39:56 |
| 14 | 0000000002800000008738 | 2015-10-06 10:12:32 | 2015-10-06 10:12:52 |
| 15 | 0000000002800000008741 | 2015-10-06 10:17:30 | 2015-10-06 10:17:30 |
| 16 | 0000000002800000008741 | 2015-10-05 16:50:40 | 2015-10-05 16:50:40 |
+----+------------------------+---------------------+---------------------+
来源：https://stackoverflow.com/questions/33104074/select-duplicates-query-returns-duplicates-mysql