mysql 将多个查询结果合并成一行

mysql中的多行查询结果合并成一个SELECT GROUP_CONCAT(md.data1) FROM DATA md,contacts cc WHERE md.conskey=cc.id AND md.mimetype_id= 5 AND md.user_id=17：利用函数：group_concat(),实现一个ID对应多个名称时，原本为多行数据，把名称合并成一行，如|1 | 10,20,20| 本文通过实例介绍了MySQL中的group_concat函数的使用方法，比如select group_concat(name) 。MySQL中group_concat函数完整的语法如下：group_concat([DISTINCT] 要连接的字段 [Order BY ASC/DESC 排序字段] [Separator '分隔符'])基本查询 mysql> select * from aa;+------+------+| id| name |+------+------+|1 | 10||1 | 20||1 | 20||2 | 20||3 | 200 ||3 | 500 |+------+------+6 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(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 ';') from aa 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)