In MySQL, is there a way to turn column records into a list?

Yes, we can turn a column records into a list using the MySQL GROUP_CONCAT(). Let us first create a table −

mysql> create table DemoTable
   -> (
   -> ClientId int,
   -> ClientName varchar(20)
   -> );
Query OK, 0 rows affected (0.88 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable values(100,'Chris');
Query OK, 1 row affected (0.54 sec)
mysql> insert into DemoTable values(100,'Robert');
Query OK, 1 row affected (0.14 sec)
mysql> insert into DemoTable values(100,'Adam');
Query OK, 1 row affected (0.14 sec)
mysql> insert into DemoTable values(100,'David');
Query OK, 1 row affected (0.13 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable;

This will produce the following output −

+----------+------------+
| ClientId | ClientName |
+----------+------------+
|      100 | Chris      |
|      100 | Robert     |
|      100 | Adam       |
|      100 | David      |
+----------+------------+
4 rows in set (0.00 sec)

Here is the query to turn column records into a list −

mysql> select ClientId,group_concat(ClientName separator ',') from DemoTable group by ClientId;

This will produce the following output −

+----------+----------------------------------------+
| ClientId | group_concat(ClientName separator ',') |
+----------+----------------------------------------+
|      100 | Chris,Robert,Adam,David               |
+----------+----------------------------------------+
1 row in set (0.00 sec)