How can I get maximum and minimum values in a single MySQL query?

To get maximum and minimum values in a single query, use the aggregate function min() and max(). Let us first create a table:

mysql> create table DemoTable
(
   FirstValue int,
   SecondValue int
);
Query OK, 0 rows affected (0.66 sec)

Following is the query to insert some records in the table using insert command:

mysql> insert into DemoTable values(10,30);
Query OK, 1 row affected (0.18 sec)
mysql> insert into DemoTable values(30,60);
Query OK, 1 row affected (0.15 sec)
mysql> insert into DemoTable values(100,500);
Query OK, 1 row affected (0.10 sec)
mysql> insert into DemoTable values(50,80);
Query OK, 1 row affected (0.18 sec)

Following is the query to display records from the table using select command:

mysql> select *from DemoTable;

This will produce the following output

+------------+-------------+
| FirstValue | SecondValue |
+------------+-------------+
|         10 |          30 |
|         30 |          60 |
|        100 |         500 |
|         50 |          80 |
+------------+-------------+
4 rows in set (0.00 sec)

Following is the query to get maximum and minimum values in a single query:

mysql> select min(FirstValue),min(SecondValue),max(FirstValue),max(SecondValue) from DemoTable;

This will produce the following output:

+-----------------+------------------+-----------------+------------------+
| min(FirstValue) | min(SecondValue) | max(FirstValue) | max(SecondValue) |
+-----------------+------------------+-----------------+------------------+
|              10 |               30 |             100 |              500 |
+-----------------+------------------+-----------------+------------------+
1 row in set (0.00 sec)