我需要从第二个表中选择一些行,并以逗号分隔的字符串连接.查询功能很好,除了一个问题 – 它总是选择所有行并忽略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)
完整查询:
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