请教sql查询2张表的问题:
A表为
id title picid
其中picid存储信息为
a:4:{s:6:"attach";s:2:"74";s:9:"show_type";s:1:"0";s:9:"user_bind";s:1:"1";s:10:"topic_bind";s:0:"";}
B表为
p_id purl
我首先通过查询A表获得了picid字段中的attach数据,输出为数组形式为
aryy{
【0】74
【1】88
....
}
那么我如何通过查询A表得到的attach去查询B表 p_id 为74 88的匹配id呢?
能给个代码解释下吗?
回复讨论(解决方案)
设第一步得到的数组为
$ar = array(74, 88);
则有
$sql = 'select * from B表 where p_id in (' . join(',', $ar) . ')';
如果 picid 中 attach 出现的次序是固定的话,还可以直接关联两表查询
比如
select p_id, purl from B表, A表 where p_id = SUBSTRING_INDEX(SUBSTRING_INDEX(picid, 4), '"', -1)
设第一步得到的数组为
$ar = array(74, 88);
则有
$sql = 'select * from B表 where p_id in (' . join(',', $ar) . ')';
如果 picid 中 attach 出现的次序是固定的话,还可以直接关联两表查询
如果出现次序不是固定的呢?能关联两表查询吗
用 LOCATE 函数先定位,应该也是可以的

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