How to order or choose rows in MySQL GROUP BY clause?
Let us first create a table −
mysql> create table DemoTable1572
-> (
-> StudentId int,
-> StudentMarks int,
-> StudentName varchar(20)
-> );
Query OK, 0 rows affected (0.56 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable1572 values(1,79,'Sam');
Query OK, 1 row affected (0.10 sec)
mysql> insert into DemoTable1572 values(2,89,'Chris');
Query OK, 1 row affected (0.12 sec)
mysql> insert into DemoTable1572 values(3,98,'David');
Query OK, 1 row affected (0.22 sec)
mysql> insert into DemoTable1572 values(4,79,'Bob');
Query OK, 1 row affected (0.10 sec)
Display all records from the table using select statement −
mysql> select * from DemoTable1572;
This will produce the following output −
+-----------+--------------+-------------+
| StudentId | StudentMarks | StudentName |
+-----------+--------------+-------------+
| 1 | 79 | Sam |
| 2 | 89 | Chris |
| 3 | 98 | David |
| 4 | 79 | Bob |
+-----------+--------------+-------------+
4 rows in set (0.00 sec)
Here is the query to order or choose rows in MySQL GROUP BY clause −
mysql> select * from DemoTable1572
-> where StudentId in (select min(StudentId) from DemoTable1572 group by StudentMarks);
This will produce the following output −
+-----------+--------------+-------------+
| StudentId | StudentMarks | StudentName |
+-----------+--------------+-------------+
| 1 | 79 | Sam |
| 2 | 89 | Chris |
| 3 | 98 | David |
+-----------+--------------+-------------+
3 rows in set (0.10 sec)
Published on 16-Dec-2019 10:31:23
