mysql - 使用 union、join 和 limit 查询(不工作)

Question

遇到问题请帮忙

sql = mysqli_query($con, "


SELECT piadi, debtorfullName, ClientAddress, mobilePhone, principalAmount, totalAmount, status, product_name,comment ,postdate 
FROM portfeli_0 
INNER JOIN komentarebi 
ON portfeli_0.piadi=komentarebi.person_id 
WHERE portfeli_0.user='$user'

UNION ALL 
SELECT piadi, debtorfullName, ClientAddress, mobilePhone, principalAmount, totalAmount, status, product_name,comment ,postdate 
FROM portfeli_1 
INNER JOIN komentarebi 
ON portfeli_1.piadi=komentarebi.person_id 
WHERE portfeli_1.user='$user' 

");

在 komentarebi 中，我有多个具有相同 person_id 的记录，我必须只取其中的一个，这可能吗？

Answer 1

这样 limit 就可以了

(SELECT piadi, debtorfullName, ClientAddress, mobilePhone, principalAmount, totalAmount, status, product_name,comment ,postdate 
FROM portfeli_0 
INNER JOIN komentarebi 
ON portfeli_0.piadi=komentarebi.person_id 
WHERE portfeli_0.user='$user'
LIMIT 1)

UNION ALL 
(SELECT piadi, debtorfullName, ClientAddress, mobilePhone, principalAmount, totalAmount, status, product_name,comment ,postdate 
FROM portfeli_1 
INNER JOIN komentarebi 
ON portfeli_1.piadi=komentarebi.person_id 
WHERE portfeli_1.user='$user' 
LIMIT 1)