MySQL聚合函数GROUP_CONCAT()实现合并多个记录
语法如下：
group_concat([DISTINCT] 要连接的字段 [Order BY ASC/DESC 排序字段] [Separator '分隔符'])
一般配合group by 一起使用。
举例:
以id分组，把name字段的值打印在一行，逗号分隔(默认)
mysql> select id,group_concat(name) from aa group by id;
+------+--------------------+
| id| group_concat(name) |
+------+--------------------+
|1 | 10,20,20|
|2 | 20 |
|3 | 200,500|
+------+--------------------+
3 rows in set (0.00 sec)以id分组，把name字段的值打印在一行，分号分隔
mysql> select id,group_concat(name separator ';') fromaa group by id;
+------+----------------------------------+
| id| group_concat(name separator ';') |
+------+----------------------------------+
|1 | 10;20;20 |
|2 | 20|
|3 | 200;500 |
+------+----------------------------------+
3 rows in set (0.00 sec)以id分组，把去冗余的name字段的值打印在一行，逗号分隔
mysql>select id,group_concat(distinct name) from aa group by id;
+------+-----------------------------+
| id| group_concat(distinct name) |
+------+-----------------------------+
|1 | 10,20|
|2 | 20 |
|3 | 200,500 |
+------+-----------------------------+
3 rows in set (0.00 sec)以id分组，把name字段的值打印在一行，逗号分隔，以name排倒序
mysql> select id,group_concat(name order by name desc)from aa group by id;
+------+---------------------------------------+
| id| group_concat(name order by name desc) |
+------+---------------------------------------+
|1 | 20,20,10 |
|2 | 20|
|3 | 500,200|
+------+---------------------------------------+
3 rows in set (0.00 sec)
Tag标签:「函数 mysql GROUP_CONCAT 聚合」更新时间:「2021-11-03 21:15:55」阅读次数:「800」