mysql>>字符串拼接

+表结构

--------+------------+------------+-----------+--------+------------+
| emp_no | birth_date | first_name | last_name | gender | hire_date  |
+--------+------------+------------+-----------+--------+------------+
|  10001 | 1953-09-02 | Georgi     | Facello   | M      | 1986-06-26 |
|  10002 | 1964-06-02 | Bezalel    | Simmel    | F      | 1985-11-21 |
|  10003 | 1959-12-03 | Parto      | Bamford   | M      | 1986-08-28 |
|  10004 | 1954-05-01 | Chirstian  | Koblick   | M      | 1986-12-01 |
|  10005 | 1955-01-21 | Kyoichi    | Maliniak  | M      | 1989-09-12 |
|  10006 | 1953-04-20 | Anneke     | Preusig   | F      | 1989-06-02 |
|  10007 | 1957-05-23 | Tzvetan    | Zielinski | F      | 1989-02-10 |
|  10008 | 1958-02-19 | Saniya     | Kalloufi  | M      | 1994-09-15 |
|  10009 | 1952-04-19 | Sumant     | Peac      | F      | 1985-02-18 |
|  10010 | 1963-06-01 | Duangkaew  | Piveteau  | F      | 1989-08-24 |
+--------+------------+------------+-----------+--------+------------+

#查询结果集
#把firstname和lastname以-的方式拼接起来

select concat (first_name,'-',last_name) as name from employees limit 10;

结果示例
+--------------------+
| name               |
+--------------------+
| Georgi-Facello     |
| Bezalel-Simmel     |
| Parto-Bamford      |
| Chirstian-Koblick  |
| Kyoichi-Maliniak   |
| Anneke-Preusig     |
| Tzvetan-Zielinski  |
| Saniya-Kalloufi    |
| Sumant-Peac        |
| Duangkaew-Piveteau |
+--------------------+