Suppose you have two tables. Table 1: Teacher Staff ID, Staff Name A001 Alex A002 Peter A003 Mary Table 1: Student Staff ID, Staff Name A001 Student A A001 Student B A001 Student C A002 Student A A003 Student A A003 Student B A003 Student A How you generate a SQL Table, to show the Staff ID, Staff Name and No of Student being taught; ie A001 Alex 4 A002 Peter 2 A003 Mary 1

select Teacher.Staff_id,Teacher.Staff_Name,count(Student.Staff_Name) from Teacher,Student where Teacher.Staff_id=Student.Staff_id group by Teacher.Staff_id,Teacher.Staff_Name ----------------------------------------------------------- 未測試過, 不過應該對 一陣紅光閃過 夾雜著V-Twin獨特的厚實聲浪 也聞到了高辛烷汽油燃燒後的焦油味 雙碟煞就像是戰神的雙翼-只祝福最剽悍的戰士 天生具有灼傷地表的能力 來吧!看到尾燈就算妳贏.......

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一陣紅光閃過
夾雜著V-Twin獨特的厚實聲浪
也聞到了高辛烷汽油燃燒後的焦油味
雙碟煞就像是戰神的雙翼-只祝福最剽悍的戰士
天生具有灼傷地表的能力
來吧!看到尾燈就算妳贏.......

引言: select Teacher.Staff_id,Teacher.Staff_Name,count(Student.Staff_Name) from Teacher,Student where Teacher.Staff_id=Student.Staff_id group by Teacher.Staff_id,Teacher.Staff_Name ----------------------------------------------------------- 未測試過, 不過應該對 一陣紅光閃過 夾雜著V-Twin獨特的厚實聲浪 也聞到了高辛烷汽油燃燒後的焦油味 雙碟煞就像是戰神的雙翼-只祝福最剽悍的戰士 天生具有灼傷地表的能力 來吧!看到尾燈就算妳贏.......

應該只要count(*)就可以了..