删除mysql group_concat选定的行

Question

Although this question was asked two years ago the solutions did not use group_concat. so keeping it brief given a table

id    name
1     Tim
2     Sam
3     Bob
4     Joe
5     Ali
6     Kay
7     Bob
8     Joe

running the following

select name, count(*) c, group_concat(id) rows
  from table
 group by name
having c > 1;

gives

name   c   rows
Bob    2   3,7
Joe    2   4,8

is is possible to then remove rows 3,7,4 and 8 from my table without writing a script? I think I do need to use group_concat because in reality my "name" column is a concatenation of three columns in the table.

Answer 1

SELECT count(`access`.id) as 
extra_access,`access`.perm_role_id,group_concat(temp.extra_id) as extra_ids
FROM `access`  
INNER JOIN(  
SELECT `access`.id,perm_role_id,perm_module_id,group_concat(id) as extra_id
FROM `access`
GROUP BY perm_role_id,perm_module_id     
HAVING COUNT(id) =1  
)temp ON access.id= temp.id GROUP BY perm_role_id

Use join again and concat again for this

Answer 2

If you want to remove the duplicate row, try this

DELETE from table where id NOT IN (select id from table GROUP BY name having count(*) = 1)

delete all rows which are not unique