Mysql 有条款问题

使用中的Employee和Department表

我正在尝试建立另一个组合表，显示在总部和研究部门工作的员工人数

到目前为止，我已经试过了，但在having子句上不断出现错误。有什么建议吗

mysql> select e.fname, d.dname
    -> from department d
    -> inner join employee e on e.dno = d.dnumber
    -> group by e.fname
    -> having d.dname='Headquarters','Research';
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to
use near ''Research'' at line 5
mysql> select e.fname, d.dname
    -> from department d
    -> inner join employee e on e.dno = d.dnumber
    -> group by e.fname
    -> having d.dname=1,5;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to
use near '5' at line 5

---

在

WHERE

子句中使用

SELECT...
FROM...
WHERE d.dname IN ('Headquarters','Research')
GROUP BY...

不想挑拨离间，但可以使用having子句吗？试试看
SELECT。。。从…起分组依据……在（‘总部’、‘研究’）中有d.d名称