用於加入兩個查詢的MySQL查詢

Question

我有一個mysql表，每行有一個學期的註冊號，dob，學生姓名，性別，總分數。 我想在單個SQL查詢中以總分數降序獲得10個男孩和5個女孩的記錄。

Answer 1

我的MySQL的方言是生鏽的，但這應該做的伎倆

(SELECT * FROM Students WHERE sex = 'Male' ORDER BY TotalMarks DESC LIMIT 10) 
UNION ALL 
(SELECT * FROM Students WHERE sex = 'Female' ORDER BY TotalMarks DESC LIMIT 5) 

這是一個單一的查詢，請注意。

Answer 2

試試這個代碼：

select 
    a.studentID, 
    a.studentName, 
    a.dob, 
    a.totalMark 
from 
(
    select 
     studentID, 
     studentName, 
     dob, 
     totalMark 
    from 
     students 
    where 
     sex='M' 
    order by 
     studentMark desc 
    limit 10 
    union all 
    select 
     studentID, 
     studentName, 
     dob, 
     totalMark 
    from 
     students 
    where 
     sex='F' 
    order by 
     totalMark desc 
    limit 5 
) 
order by 
    totalMark desc 

Answer 3

試試這個

select * from 
    (select reg_number, dob, student_name, sex, total_marks where sex='male' 
    order by total_marks desc limit 10 
    union 
    select reg_number, dob, student_name, sex, total_marks where sex='female' 
    order by total_marks desc limit 5) a order by total_marks desc