帮忙看一个sql，谢谢！

类似于这种
people表
+------------+------------+
| department | name       |
+------------+------------+
| 1          | zhangsan   |
| 1          | lisi       |
| 2          | wangwu     |
| 2          | zhaoliu    |
+------------+------------+
department表
+------+--------+
| id   | name   |
+------+-----  -+
| 1    | dept1  |
| 2    | dept2  |
+------+------  +我写的sql查询出来的结果：第三列为某人所属部门的人头数
select p.name, d.name, c.c from people p, department d, (select count(nam
e) c, department from people group by department) c where p.department = d.id an
d p.department = c.department;
+------------+------+---+
| name       | name | c |
+------------+------+---+
| zhangsan   | dept1| 2 |
| lisi       | dept1| 2 |
| wangwu     | dept2| 2 |
| zhaoliu    | dept2| 2 |
+------------+------+---+
但是我需要的结果是：即每个部门只有第一个人有部门人数这一列
+------------+------+---+
| name       | name | c |
+------------+------+---+
| zhangsan   | dept1| 2 |
| lisi       | dept1|   |
| wangwu     | dept2| 2 |
| zhaoliu    | dept2|   |
+------------+------+---+请问应该怎么写sql，谢谢sql