MySQL Query to Skip Duplicates and Select Unique Values

The syntax is as follows to skip the duplicate value and select only one from the duplicated values −

select min(yourColumnName1),yourColumnName2 from yourTableName group by
yourColumnName2;

To understand the above syntax, let us create a table. The query to create a table is as follows −

mysql> create table doNotSelectDuplicateValuesDemo
   -> (
   -> User_Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,
   -> User_Name varchar(20)
   -> );
Query OK, 0 rows affected (0.78 sec)

Now you can insert some records in the table using insert command. The query is as follows −

mysql> insert into doNotSelectDuplicateValuesDemo(User_Name) values('John');
Query OK, 1 row affected (0.15 sec)
mysql> insert into doNotSelectDuplicateValuesDemo(User_Name) values('Carol');
Query OK, 1 row affected (0.09 sec)
mysql> insert into doNotSelectDuplicateValuesDemo(User_Name) values('Carol');
Query OK, 1 row affected (0.17 sec)
mysql> insert into doNotSelectDuplicateValuesDemo(User_Name) values('Carol');
Query OK, 1 row affected (0.08 sec)
mysql> insert into doNotSelectDuplicateValuesDemo(User_Name) values('Sam');
Query OK, 1 row affected (0.28 sec)
mysql> insert into doNotSelectDuplicateValuesDemo(User_Name) values('Mike');
Query OK, 1 row affected (0.19 sec)
mysql> insert into doNotSelectDuplicateValuesDemo(User_Name) values('Bob');
Query OK, 1 row affected (0.16 sec)
mysql> insert into doNotSelectDuplicateValuesDemo(User_Name) values('David');
Query OK, 1 row affected (0.21 sec)
mysql> insert into doNotSelectDuplicateValuesDemo(User_Name) values('Maxwell');
Query OK, 1 row affected (0.13 sec)
mysql> insert into doNotSelectDuplicateValuesDemo(User_Name) values('Bob');
Query OK, 1 row affected (0.11 sec)
mysql> insert into doNotSelectDuplicateValuesDemo(User_Name) values('Ramit');
Query OK, 1 row affected (0.16 sec)

Display all records from the table using select statement. The query is as follows −

mysql> select *from doNotSelectDuplicateValuesDemo;

Here is the output −

+---------+-----------+
| User_Id | User_Name |
+---------+-----------+
| 1       | John      |
| 2       | Carol     |
| 3       | Carol     |
| 4       | Carol     |
| 5       | Sam       |
| 6       | Mike      |
| 7       | Bob       |
| 8       | David     |
| 9       | Maxwell   |
| 10      | Bob       |
| 11      | Ramit     |
+---------+-----------+
11 rows in set (0.00 sec)

Here is the query to skip the duplicate value and select only one from the duplicated values −

mysql> select min(User_Id),User_Name from doNotSelectDuplicateValuesDemo group by
User_Name;

Here is the output −

+--------------+-----------+
| min(User_Id) | User_Name |
+--------------+-----------+
| 1            | John      |
| 2            | Carol     |
| 5            | Sam       |
| 6            | Mike      |
| 7            | Bob       |
| 8            | David     |
| 9            | Maxwell   |
| 11           | Ramit     |
+--------------+-----------+
8 rows in set (0.07 sec)