具有特定列名SQL的GROUP BY

Question

示例我的表名稱為DEPARTMENT

//DEPARTMENT
D#
--------
1
2
3

現在有一個項目表

//Project
P#      D#
-----------
1       1
2       1
3       2
4       1

因此，在使用提示符顯示所有信息時，我應如何使用具有特定列名的分組依據？

Enter Department Number : 1

D#      total project
---------------------
1            3

到目前為止，我已經做到了

ACCEPT dno PROMPT 'Enter Department Number: ' 
SELECT DNAME FROM DEPARTMENT WHERE D#=&dno;
SELECT count(*) from PROJECT where D#=&dno;

Answer 1

用這個

select DNAME, count(Project) AS "total project" FROM DEPARTMENT d, PROJECT p
WHERE d.dno=p.dno and D.DNO=&dno  group by DNAME;

只求總數

select  count(Project) AS "total project" FROM DEPARTMENT d, PROJECT p
WHERE d.dno=p.dno and D.DNO=&dno  group by DNAME;

Answer 2

嘗試在兩個表之間進行JOIN，

ACCEPT dno PROMPT 'Enter Department Number: ' 
SELECT DNAME, count(*)
    FROM DEPARTMENT d, PROJECT p
    WHERE d.dno=p.dno and d.dno=&dno
    group by d.DNAME;

編輯

顯示dno和DNAME與項目計數一起

ACCEPT dno PROMPT 'Enter Department Number: ' 
SELECT d.dno,DNAME, count(*) as 'total'
    FROM DEPARTMENT d, PROJECT p
    WHERE d.dno=p.dno and d.dno=&dno
    group by d.dno,DNAME;