我需要從第二個表中選擇一些行並將它們連接在以逗號分隔的字符串中。除一個問題外,查詢效果很好 - 它總是選擇所有行並忽略LIMIT。LIMIT在帶有GROUP_CONCAT的查詢中被忽略
這是我的查詢的一部分,它可以獲取該字符串並忽略LIMIT:
select
group_concat(value order by `order` asc SEPARATOR ', ')
from slud_data
left join slud_types on slud_types.type_id=slud_data.type_id
where slud_data.product_id=18 and value!='' and display=0 limit 3;
// Result:
+---------------------------------------------------------+
| group_concat(value order by `order` asc SEPARATOR ', ') |
+---------------------------------------------------------+
| GA-XXXX, Bentley, CONTINENTAL FLYING SPUR, 2006 |
+---------------------------------------------------------+
// Expected result: (only 3 comma-separated records, not 4)
全面查詢:
SELECT *,product_id id,
(select group_concat(value order by `order` asc SEPARATOR ', ') from slud_data left join slud_types on slud_types.type_id=slud_data.type_id where slud_data.product_id=t1.product_id and value!='' and display=0 limit 3) text
FROM slud_products t1
WHERE
now() < DATE_ADD(date,INTERVAL +ttl DAY) and activated=1
ORDER BY t1.date desc