MySQL 是否可以按一列分组并选择所有数据？

是的，您可以使用group_concat（）来实现。让我们首先创建一个表 –

mysql> create table groupByOneSelectAll
   -> (
   -> StudentDetails varchar(100),
   -> StudentName varchar(100)
   -> );
Query OK, 0 rows affected (0.91 sec)

以下是使用插入命令将一些记录插入表中的查询 –

mysql> insert into groupByOneSelectAll values('StudentFirstName','John');
Query OK, 1 row affected (0.14 sec)

mysql> insert into groupByOneSelectAll values('StudentFirstName','Chris');
Query OK, 1 row affected (0.21 sec)

mysql> insert into groupByOneSelectAll values('StudentFirstName','Robert');
Query OK, 1 row affected (0.65 sec)

mysql> insert into groupByOneSelectAll values('StudentFirstName','Bob');
Query OK, 1 row affected (0.13 sec)

mysql> insert into groupByOneSelectAll values('StudentFirstName','David');
Query OK, 1 row affected (0.15 sec)

以下是使用select语句从表中显示所有记录的查询 –

mysql> select * from groupByOneSelectAll;

这将产生以下输出 –

+------------------+-------------+
| StudentDetails   | StudentName |
+------------------+-------------+
| StudentFirstName | John        |
| StudentFirstName | Chris       |
| StudentFirstName | Robert      |
| StudentFirstName | Bob         |
| StudentFirstName | David       |
+------------------+-------------+
5 rows in set (0.00 sec)

以下是按单个列分组的查询 –

mysql> select StudentDetails,group_concat(StudentName) from groupByOneSelectAll group
by StudentDetails;

这将产生以下输出 –

+------------------+-----------------------------+
| StudentDetails   | group_concat(StudentName)   |
+------------------+-----------------------------+
| StudentFirstName | John,Chris,Robert,Bob,David |
+------------------+-----------------------------+
1 row in set (0.05 sec)

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