Use group_concat() function from MySQL to concatenate. Let us first create a table −
mysql> create table DemoTable -> ( -> Subject varchar(10) -> ); Query OK, 0 rows affected (0.43 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable values('C');
Query OK, 1 row affected (0.20 sec)
mysql> insert into DemoTable values('C++');
Query OK, 1 row affected (0.25 sec)
mysql> insert into DemoTable values('C++');
Query OK, 1 row affected (0.06 sec)
mysql> insert into DemoTable values('MongoDB');
Query OK, 1 row affected (0.17 sec)
mysql> insert into DemoTable values('MySQL');
Query OK, 1 row affected (0.14 sec)
mysql> insert into DemoTable values('MongoDB');
Query OK, 1 row affected (0.14 sec)
mysql> insert into DemoTable values('MongoDB');
Query OK, 1 row affected (0.34 sec)
mysql> insert into DemoTable values('Java');
Query OK, 1 row affected (0.18 sec)
mysql> insert into DemoTable values('Java');
Query OK, 1 row affected (0.10 sec)
Display all records from the table using select statement:mysql> select *from DemoTable;
This will produce the following output −
+---------+ | Subject | +---------+ | C | | C++ | | C++ | | MongoDB | | MySQL | | MongoDB | | MongoDB | | Java | | Java | +---------+ 9 rows in set (0.00 sec)
Following is the query to concatenate SQL distinct query results into a string −
mysql> select group_concat(tbl.sub) from (select Subject sub from DemoTable group by Subject ) tbl;
This will produce the following output −
+--------------------------+ | group_concat(tbl.sub) | +--------------------------+ | C,C++,MongoDB,MySQL,Java | +--------------------------+ 1 row in set (0.04 sec)
