如何在mysql中将多个值组合为一个值？

GROUP_CONCAT([DISTINCT] expr [,expr ...]
             [ORDER BY {unsigned_integer | col_name | expr}
                 [ASC | DESC] [,col_name ...]]
             [SEPARATOR str_val])

+----+-------+---------+
| id | name  | course  |
+----+-------+---------+
|  1 | Alice | Math    |
|  2 | Bob   | English |
|  3 | Alice | Science |
|  4 | Bob   | Math    |
+----+-------+---------+

SELECT name, GROUP_CONCAT(course SEPARATOR ',') AS courses
FROM students
GROUP BY name;

+-------+-----------------+
| name  | courses         |
+-------+-----------------+
| Alice | Math,Science    |
| Bob   | English,Math    |
+-------+-----------------+