在 MySQL 中将多行合并成一个逗号分隔列表?
要将多行合并成一个逗号分隔列表,请使用 GROUP_CONCAT() 方法。我们首先创建一个表 −
mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Name varchar(30), Marks int ); Query OK, 0 rows affected (0.52 sec)
使用 insert 命令在表中插入一些记录 −
mysql> insert into DemoTable(Name,Marks) values('John',67); Query OK, 1 row affected (0.25 sec) mysql> insert into DemoTable(Name,Marks) values('Carol',69); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable(Name,Marks) values('Sam',69); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable(Name,Marks) values('David',78); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable(Name,Marks) values('Chris',69); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable(Name,Marks) values('Bob',67); Query OK, 1 row affected (0.17 sec)
使用 select 语句从表中显示所有记录 −
mysql> select *from DemoTable;
输出
+----+-------+-------+ | Id | Name | Marks | +----+-------+-------+ | 1 | John | 67 | | 2 | Carol | 69 | | 3 | Sam | 69 | | 4 | David | 78 | | 5 | Chris | 69 | | 6 | Bob | 67 | +----+-------+-------+ 6 rows in set (0.00 sec)
以下是 MySQL 中将多行合并成一个逗号分隔列表的查询 −
mysql> SELECT Marks, GROUP_CONCAT(Name ORDER BY Name ASC SEPARATOR ', ') from DemoTable GROUP BY Marks;
输出
+-------+-----------------------------------------------------+ | Marks | GROUP_CONCAT(Name ORDER BY Name ASC SEPARATOR ', ') | +-------+-----------------------------------------------------+ | 67 | Bob, John | | 69 | Carol, Chris, Sam | | 78 | David | +-------+-----------------------------------------------------+ 3 rows in set (0.00 sec)
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