MySQL 连接运算符
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MySQL concatenation operator
提问by user2201462
I don't know concatenation operator for MySQL.
我不知道 MySQL 的连接运算符。
I have tried this code for concatenation:
我已经尝试使用此代码进行连接：
SELECT vend_name || ' (' || vend_country || ')'
FROM Vendors
ORDER BY vend_name;
But it didn't work. Which operator should I use to concatenate strings?
但它没有用。我应该使用哪个运算符来连接字符串？
回答by 200_success
||is the ANSI standard string concatenation operator, supported by most databases (notably not MS SQL Server). MySQL also supports it, but you have to SET sql_mode='PIPES_AS_CONCAT';or SET sql_mode='ANSI';first.
||是 ANSI 标准字符串连接运算符，大多数数据库（尤其不是 MS SQL Server）都支持。MySQL 也支持它，但你必须SET sql_mode='PIPES_AS_CONCAT';或SET sql_mode='ANSI';首先。
回答by codingbiz
You were using ORACLE type of concatenation. MySQL's Should be
您正在使用 ORACLE 类型的连接。MySQL的应该是
SELECT CONCAT(vend_name, '(', vend_country, ')')
Call the CONCAT()function and separate your values with commas.
调用该CONCAT()函数并用逗号分隔您的值。
回答by Akshay Joy
MySQL CONCAT function is used to concatenate two strings to form a single string. Try out following example:
MySQL CONCAT 函数用于连接两个字符串以形成单个字符串。试试下面的例子：
mysql> SELECT CONCAT('FIRST ', 'SECOND');
+----------------------------+
| CONCAT('FIRST ', 'SECOND') |
+----------------------------+
| FIRST SECOND |
+----------------------------+
1 row in set (0.00 sec)
To understand CONCAT function in more detail consider an employee_tbl table which is having following records:
要更详细地了解 CONCAT 函数，请考虑具有以下记录的 employee_tbl 表：
mysql> SELECT CONCAT(id, name, work_date)
-> FROM employee_tbl;
+-----------------------------+
| CONCAT(id, name, work_date) |
+-----------------------------+
| 1John2007-01-24 |
| 2Ram2007-05-27 |
| 3Hyman2007-05-06 |
| 3Hyman2007-04-06 |
| 4Jill2007-04-06 |
| 5Zara2007-06-06 |
| 5Zara2007-02-06 |
+-----------------------------+
回答by T.S.
Whats good about using concatis that you can pass different data type columns and concat string representations
使用的好处concat是您可以传递不同的数据类型列和连接字符串表示
SELECT concat('XXX', 10.99, 'YYY', 3, 'ZZZ', now(3)) as a;
Output
输出
a
-----
XXX10.99YYY3ZZZ2018-09-21 15:20:25.106
一
-----
XXX10.99YYY3ZZZ2018-09-21 15:20:25.106
回答by Kumar Anil Chaurasiya
Simply you can use CONCATkeyword to concatenate the Strings..
You can use it like
简单地你可以使用CONCAT关键字来连接字符串..你可以像这样使用它
SELECT CONCAT(vend_name,'',vend_country) FROM vendors ORER BY name;
回答by Xeno
You have to set pipes as concat every time before you run a query using pipes as a concatenate operator.
每次使用管道作为连接运算符运行查询之前，您都必须将管道设置为连接。
