A detailed description of MySQL's Group_concat function

function Syntax:

Group_concat ([DISTINCT] field to connect [order by sort field Asc/desc] [Separator ' delimiter '])

The following examples illustrate:

SELECT * from  goods;

+------+------+
| id| price|
+------+------+
| 10|
| 20|
| 20|
| 20|
|3 | 200 |
|3 | 500 |
+------+------+
6 rows in Set (0.00 sec)

GROUP by ID, put the value of the Price field on the same line print out, comma separated (default)

Select ID, group_concat (price) from goods group by  ID;

+------+--------------------+
| id| Group_concat (Price) |
+------+--------------------+
| 10,20,20|
| 20 |
|3 | 200,500|
+------+--------------------+
3 Rows in Set (0.00 sec)

Group by ID, print the value of the Price field on one line, separated by semicolons

Select Id,group_concat (Price separator '; ') from goodsGroup by ID;

+------+----------------------------------+
| id| Group_concat (Price separator '; ') |
+------+----------------------------------+
| 10;20;20 |
| 20|
|3 | 200;500 |
+------+----------------------------------+
3 Rows in Set (0.00 sec)

Group by ID, print the value of the Price field, which removes redundant redundancy, in one line, separated by commas
Select Id,group_concat (distinct price) from goods  Group by ID;

+------+-----------------------------+
| id| Group_concat (distinct price) |
+------+-----------------------------+
| 10,20|
| 20 |
|3 | 200,500 |
+------+-----------------------------+
3 Rows in Set (0.00 sec)

GROUP by ID, print the value of the Price field on one line, comma separated, in reverse order of Price Arrange
Select Id,group_concat (Price ORDER BY price DESC) from the goods group by ID;

+------+---------------------------------------+
| id| Group_concat (Price ORDER BY price desc) |
+------+---------------------------------------+
| 20,20,10 |
| 20|
|3 | 500,200|
+------+---------------------------------------+
3 Rows in Set (0.00 sec)

A detailed description of MySQL's Group_concat function