PostgreSQL's array_agg() and array_to_string in MySQL

Question

I wonder if there's a counterpart of array_agg() and array_to_string of PostgreSQL in MySQL (Or anything close to this function at least) I haven't had any luck on my research trying to find something similar to this two. For non-PostgreSQL users, here's how it works.
Normally, executing:

SELECT my_column FROM my_table;

Will result to:

--------------
| my_column  |
|------------|
|   DATA1    |
|   DATA2    |
|   DATA3    |
|   DATA4    |
--------------

On the other hand, executing the statement:

SELECT array_agg(my_column) FROM my_table;

Will result to:
A single row with all the data from my_column.

-----------------------------------
|       array_agg(my_column)      |
|---------------------------------|
|{"DATA1","DATA2","DATA3","DATA4"}|
-----------------------------------

And array_to_string, as the function name says, it converts the array into a single String.
Converting the array_agg(my_column) will return the following:

-------------------------
|                       |
|-----------------------|
|DATA1,DATA2,DATA3,DATA4|
-------------------------

Depending on your separator. In my case, it's comma.

*******************Edit(SOLUTION)*******************

Solution (Written by IgorRomanchenko):

SELECT GROUP_CONCAT(my_column SEPARATOR ',');

Answer 1

MySQL does not have bult in array type, but you can use string aggregation (like GROUP_CONCAT) to aggregate multiple values to a single string.