SQL查詢含有2的結果集

Question

select name from persons where gender = 'male' order by name limit 10

select name from persons where gender = 'female' order by name limit 10

我怎樣才能獲得前10名男性和第10位女性中的一個結果集（20項），與單個SQL查詢電話？這可能嗎？

Answer 1

正確的語法使用括號和union all：

(select name 
from persons 
where gender = 'male' 
order by name 
limit 10 
) union all 
(select name 
from persons 
where gender = 'female' 
order by name 
limit 10 
) 

Answer 2

這是可能的，這就是所謂的UNION

Answer 3

可以使用UNION操作。

UNION用於將結果從多個SELECT語句 組合成單個結果集。

select name from persons where gender = 'male' order by name limit 10 
UNION 
select name from persons where gender = 'female' order by name limit 10 

Answer 4

SELECT name FROM persons WHERE gender = 'male' ORDER BY name LIMIT 0,10 ; 
    UNION 
SELECT name FROM persons WHERE gender = 'female' ORDER BY name LIMIT 0,10 ; 

Answer 5

與ROW_NUMBER（）

SELECT * FROM (
SELECT ROW_NUMBER() OVER (PARTITION BY gender ORDER BY gender) row_no,* FROM Person 
) A WHERE A.row_no <= 10