将employees表中的所有员工的last_name和first_name通过(')连接起来。
CREATE TABLE `employees` (
`emp_no` int(11) NOT NULL,
`birth_date` date NOT NULL,
`first_name` varchar(14) NOT NULL,
`last_name` varchar(16) NOT NULL,
`gender` char(1) NOT NULL,
`hire_date` date NOT NULL,
PRIMARY KEY (`emp_no`));
这里分2种，一种sqlite数据库，考察||符号。
select last_name || " ' "|| first_name from employees;
mysql 只能用concat函数来连接
select concat(last_name,"‘",first_name) as name
from employees;