MySQL single table field duplicate data takes the latest SQL statement

Mysql Take the latest one for the duplicate data in a single table sql sentence

We often sql Query some related data contents in the statement . Solution we can use grouping and max（）. But this method will produce null The problem of . So we can use not exists To perform .

scene ： Get the latest data of users in the list

solve

utilize not exists

select * from temp t where not exists(select 1 from temp t2 where t.userId = t2.userId and t2.tm_create_date > t.tm_create_date)

result ：

summary ：
Try many ways , Strive to master the method that best meets the needs .