如何僅從'list'表中獲取行。 NOT PARAM TABLES

Question

我只想顯示'list'表中的行。但是，下面的代碼給出了從父表太

 mysqli_query($con, "select * from list 
     RIGHT JOIN department ON list.department_id = department.id 
     RIGHT JOIN subject ON list.subject_id = subject_id 
     RIGHT JOIN sub_subject ON list.sub_subject_id = sub_subject_id 
     order by list.id $order"); 

Answer 1

mysqli_query($con, "select list.* from list 
    Left JOIN department ON list.department_id = department.id 
    Left JOIN subject ON list.subject_id = subject_id 
    Left JOIN sub_subject ON list.sub_subject_id = sub_subject_id 
Where department.id = NULL 
And subject_id = NULL 
And sub_subject_id = NULL 
order by list.id $order");