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Mysql重点难题（2）汇总
2022-07-02 04:48:00 【且行且安~】
目录
1、按照dept_no进行汇总
按照dept_no进行汇总，属于同一个部门的emp_no按照逗号进行连接，结果给出dept_no以及连接出的结果employees
CREATE TABLE `dept_emp` (
`emp_no` int(11) NOT NULL,
`dept_no` char(4) NOT NULL,
`from_date` date NOT NULL,
`to_date` date NOT NULL,
PRIMARY KEY (`emp_no`,`dept_no`));
输出格式
| dept_no | employees |
|---|---|
| d001 | 10001,10002 |
| d002 | 10006 |
| d003 | 10005 |
| d004 | 10003,10004 |
| d00 |
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