INNER JOIN 關鍵字語法
SELECT column_name(s) FROM table_name1 INNER JOIN table_name2 ON table_name1.column_name=table_name2.column_name
題目:
請編寫 SQL 語句,將課程表 courses 和教師表 teachers 進行內連接,查詢 “Eastern Heretic” 老師所教的所有課程的課程名和課程編號 , 且結果列名分別以課程編號 id 、課程名稱 course_name 和教師姓名 teacher_name 顯示。
錯誤寫法:
? ? SELECT courses.id,courses.courses_name,teachers.teacher_name
? ? FROM teachers
? ? INNER JOIN courses
? ? ON courses.id = teachers.id where teachers.teacher_name = ?“Eastern Heretic"
正確寫法:
? ? SELECT c.id,c.name as course_name,t.name as teacher_name
? ? FROM teachers t
? ? inner join courses c on c.teacher_id=t.id
? ? WHERE t.name='Eastern Heretic'
?
?