How to group by column name and ensure the query retrieves the last update in MySQL?

Let us first create a table −

mysql> create table DemoTable621 (UserName varchar(100),UserEmailId varchar(100),UserLastPost datetime);
Query OK, 0 rows affected (0.59 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable621 values('John','John@gmail.com','2019-04-10 11:01:10');
Query OK, 1 row affected (0.47 sec)
mysql> insert into DemoTable621 values('John','John@gmail.com','2019-07-14 13:07:10');
Query OK, 1 row affected (0.15 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable621;

This will produce the following output −

+----------+----------------+---------------------+
| UserName | UserEmailId    | UserLastPost        |
+----------+----------------+---------------------+
| John     | John@gmail.com | 2019-04-10 11:01:10 |
| John     | John@gmail.com | 2019-07-14 13:07:10 |
+----------+----------------+---------------------+
2 rows in set (0.00 sec)

Following is the query to group by column name and ensure the query retrieves the last update −

mysql> select UserName,UserEmailId,max(UserLastPost) from DemoTable621 group by UserName,UserEmailId;

This will produce the following output −

+----------+----------------+---------------------+
| UserName | UserEmailId    | max(UserLastPost)   |
+----------+----------------+---------------------+
| John     | John@gmail.com | 2019-07-14 13:07:10 |
+----------+----------------+---------------------+
1 row in set (0.19 sec)