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MySQLÖÐgroup_concatº¯Êý
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group_concat([DISTINCT] ÒªÁ¬½ÓµÄ×Ö¶Î [Order BY ASC/DESC ÅÅÐò×Ö¶Î] [Separator '·Ö¸ô·û'])
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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)
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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)
ÒÔid·Ö×飬°Ñname×ֶεÄÖµ´òÓ¡ÔÚÒ»ÐУ¬·ÖºÅ·Ö¸ô
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)
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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)
ÒÔid·Ö×飬°Ñname×ֶεÄÖµ´òÓ¡ÔÚÒ»ÐУ¬¶ººÅ·Ö¸ô£¬ÒÔnameÅŵ¹Ðò
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)


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