Display all the column values in a single row separated by comma in MySQL?

For this, use GROUP_CONCAT() and CONCAT(). Let us first create a table −

mysql> create table DemoTable1807
     (
     Id int
     );
Query OK, 0 rows affected (0.00 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable1807 values(101);
Query OK, 1 row affected (0.00 sec)
mysql> insert into DemoTable1807 values(102);
Query OK, 1 row affected (0.00 sec)
mysql> insert into DemoTable1807 values(103);
Query OK, 1 row affected (0.00 sec)

Display all records from the table using select statement −

mysql> select * from DemoTable1807;

This will produce the following output −

+------+
| Id   |
+------+
|  101 |
|  102 |
|  103 |
+------+
3 rows in set (0.00 sec)

Here is the query to convert SQL query to MySQL −

mysql> select group_concat(concat('[',Id,']'))  from DemoTable1807;

This will produce the following output −

+----------------------------------+
| group_concat(concat('[',Id,']')) |
+----------------------------------+
| [101],[102],[103]                |
+----------------------------------+
1 row in set (0.00 sec)