数据库文件被同事给删了,没办法,只能重新采集数据,以前没有问题,但是这次导入数据库后,程序获取不到最新的数据$q = "SELECT fc.city_id, city_name, fang_time, IF(area is NULL,0,area), IF(taoshu is NULL,0,taoshu), fcj.id FROM f_city AS fc LEFT JOIN (SELECT * FROM f_chengjiao ORDER by fang_time DESC) AS fcj USING (city_id) GROUP BY fc.city_id";数据库我是每个片区导入数据,最后实际情况如下
我这样写能获取到 最新数据,一旦我关联表查询区域的时间,数据就乱了
SELECT city_id, IF(area is NULL,0,area), IF(taoshu is NULL,0,taoshu), fang_time FROM (SELECT * FROM f_chengjiao ORDER BY fang_time DESC) AS fcj GROUP BY city_id ORDER BY fcj.city_id ASC LIMIT 13
SELECT city_id, IF(area is NULL,0,area), IF(taoshu is NULL,0,taoshu), fang_time FROM (SELECT * FROM f_chengjiao ORDER BY fang_time DESC) AS fcj GROUP BY city_id ORDER BY fcj.city_id ASC LIMIT 13
你怎么就知道你期望的内容就一定在前 13 条里面?虽然你先 fang_time DESC 将最新的内容排在前面了
但架不住 fcj.city_id ASC 去拖后退的!
你这样做的效果只是 同一城市的记录按时间降序