在MySQL SELECT子句中添加/连接文本值？
要在select子句中添加/连接文本值，可以使用concat()函数。
让我们创建一个表
mysql> create table ConcatenatingDemo -> ( -> UserId int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> UserName varchar(20), -> UserCountryName varchar(20) -> );
现在，您可以使用insert命令在表中插入一些记录。查询如下-
mysql> insert into ConcatenatingDemo(UserName,UserCountryName) values('John','US');
mysql> insert into ConcatenatingDemo(UserName,UserCountryName) values('Carol','UK');
mysql> insert into ConcatenatingDemo(UserName,UserCountryName) values('Bob','AUS');
mysql> insert into ConcatenatingDemo(UserName,UserCountryName) values('David','US');使用select语句显示表中的所有记录。查询如下-
mysql> select *from ConcatenatingDemo;
以下是输出
+--------+----------+-----------------+ | UserId | UserName | UserCountryName | +--------+----------+-----------------+ | 1 | John | US | | 2 | Carol | UK | | 3 | Bob | AUS | | 4 | David | US | +--------+----------+-----------------+ 4 rows in set (0.00 sec)
这是用于在SELECT子句中添加/连接文本值的查询
mysql> select concat(UserName,' belongs to ( ',UserCountryName,' )') as AddingTextDemo from ConcatenatingDemo;
以下是输出
+-------------------------+ | AddingTextDemo | +-------------------------+ | John belongs to ( US ) | | Carol belongs to ( UK ) | | Bob belongs to ( AUS ) | | David belongs to ( US ) | +-------------------------+ 4 rows in set (0.00 sec)