mysql delete duplicate data in the table, (retain only one row)

The data in the example table is as follows:

According to uniqle_idThis column is used to determine whether the data is repeated
1. Check the repeated data

select uniqle_id,name from person group by uniqle_id having count(span>uniqle_id) > 1

The result is as follows:

2. Remove duplicatesColumn, only keep the row with the smallest id

delete from person where uniqle_id in (select * from(select min(uniqle_id) from person group by uniqle_idhaving count(uniqle_id) > 1) temp)and id not in(select * from(select min(id) from person group by uniqle_idhaving count(uniqle_id)> 1 )temp2)

3. Delete all duplicate lines

delete from person where uniqle_id in (select * from(select min(uniqle_id)as uniqle_id from person groupby uniqle_id having count(uniqle_id) > 1) temp)

(The purpose of temp in sql is to give the result of the sub-query an alias. If this alias is not available, an error will be reported: SQL error [1248] [42000]: Every derived table must have its own alias)