如何在 MySQL 中连接所有列?
mysqlmysqli database更新于 2025/9/18 0:12:17
首先，您需要知道表中有多少列。以下是了解列名的语法 −
show columns from yourTableName;
以下是连接所有列的语法 −
select concat(yourColumnName1,yourColumnName2,yourColumnName3,........N) from yourTableName;
首先我们创建一个表 −
mysql> create table DemoTable ( CustomerId int, CustomerName varchar(20), CustomerAge int ); Query OK, 0 rows affected (0.66 sec)
以下是了解确切列的查询 −
mysql> show columns from DemoTable;
这将产生以下输出 −
+--------------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +--------------+-------------+------+-----+---------+-------+ | CustomerId | int(11) | YES | | NULL | | | CustomerName | varchar(20) | YES | | NULL | | | CustomerAge | int(11) | YES | | NULL | | +--------------+-------------+------+-----+---------+-------+ 3 rows in set (0.00 sec)
使用 insert 命令在表中插入记录 −
mysql> insert into DemoTable values(101,'Chris',26); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values(102,'Robert',27); Query OK, 1 row affected (0.16 sec)
使用 select 语句显示表中的所有记录 −
mysql> select * from DemoTable;
这将产生以下输出 −
+------------+--------------+-------------+ | CustomerId | CustomerName | CustomerAge | +------------+--------------+-------------+ | 101 | Chris | 26 | | 102 | Robert | 27 | +------------+--------------+-------------+ 2 rows in set (0.00 sec)
以下是连接所有列的查询 −
mysql> select concat(CustomerId,CustomerName,CustomerAge) from DemoTable;
这将产生以下输出 −
+---------------------------------------------+ | concat(CustomerId,CustomerName,CustomerAge) | +---------------------------------------------+ | 101Chris26 | | 102Robert27 | +---------------------------------------------+ 2 rows in set (0.00 sec)
相关文章
有用资源
mysql 参考教程 - 该教程包含有关 mysql 的更多信息:https://www.cainiaomax.com/mysql/
