Select the maximum for each value in a MySQL table?

For this, use GROUP BY clause along with MAX(). Let us first create a table −

mysql> create table DemoTable
   -> (
   -> CountryName varchar(20),
   -> Population int
   -> );
Query OK, 0 rows affected (0.56 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable values('US',560);
Query OK, 1 row affected (0.23 sec)
mysql> insert into DemoTable values('UK',10090);
Query OK, 1 row affected (0.15 sec)
mysql> insert into DemoTable values('UK',8794);
Query OK, 1 row affected (0.19 sec)
mysql> insert into DemoTable values('US',1090);
Query OK, 1 row affected (0.21 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable;

This will produce the following output −

+-------------+------------+
| CountryName | Population |
+-------------+------------+
| US          |        560 |
| UK          |      10090 |
| UK          |       8794 |
| US          |       1090 |
+-------------+------------+
4 rows in set (0.00 sec)

Following is the query to select the maximum for each value in a MySQL table −

mysql> select CountryName,max(Population) from DemoTable group by CountryName;

This will produce the following output −

+-------------+-----------------+
| CountryName | max(Population) |
+-------------+-----------------+
| US          |            1090 |
| UK          |           10090 |
+-------------+-----------------+
2 rows in set (0.00 sec)