Select Distinct Value from One MySQL Column Only

To select distinct value from one column only, you can use aggregate function MAX() along with GROUP BY. Let us first create a table −

mysql> create table distinctFromOneColumn
   -> (
   -> StudentId int,
   -> StudentName varchar(100)
   -> );
Query OK, 0 rows affected (0.77 sec)

Following is the query to insert records in the table using insert command −

mysql> insert into distinctFromOneColumn values(1001,'John');
Query OK, 1 row affected (0.15 sec)

mysql> insert into distinctFromOneColumn values(1002,'Carol');
Query OK, 1 row affected (0.15 sec)

mysql> insert into distinctFromOneColumn values(1001,'Sam');
Query OK, 1 row affected (0.15 sec)

mysql> insert into distinctFromOneColumn values(1001,'David');
Query OK, 1 row affected (0.16 sec)

mysql> insert into distinctFromOneColumn values(1002,'Ramit');
Query OK, 1 row affected (0.15 sec)

mysql> insert into distinctFromOneColumn values(1003,'Bob');
Query OK, 1 row affected (0.21 sec)

Following is the query to display all records from the table using select statement −

mysql> select * from distinctFromOneColumn;

This will produce the following output −

+-----------+-------------+
| StudentId | StudentName |
+-----------+-------------+
| 1001      | John        |
| 1002      | Carol       |
| 1001      | Sam         |
| 1001      | David       |
| 1002      | Ramit       |
| 1003      | Bob         |
+-----------+-------------+
6 rows in set (0.00 sec)

Here is the query to select a distinct value from one column only −

mysql> select StudentId,MAX(StudentName) AS StudentName
   -> from distinctFromOneColumn
   -> group by StudentId;

This will produce the following output −

+-----------+-------------+
| StudentId | StudentName |
+-----------+-------------+
| 1001      | Sam         |
| 1002      | Ramit       |
| 1003      | Bob         |
+-----------+-------------+
3 rows in set (0.00 sec)