How MySQL removes duplicate data and preserves the data with the highest ID

title: There is a test table containing three fields id,name,sex. Q: How do I query for duplicate data?

Select Name,sex,count (*) from test GROUP by Name,sex has the count (*) >1.

Q: How do I delete duplicate data and keep the data with the largest ID?

Delete A from test a join

(Select Name,sex,count (*), Max (ID) as ID

From Test GROUP by Name,sex

Have count (*) >1) b on A.name=b.name where a.id<b.id

How MySQL removes duplicate data and preserves the data with the highest ID