#数据,条件字段,需附加的字段,表名,新字段前缀
function attach_info($r,$in='uid',$where='uid',$fields=array('uid','nick'),$table='member',$pre=''){
    $ids=array();
    foreach($r as $v)$ids[$v[$in]]=$v[$in];#获取where in 的 ids
    $res = $this->db->query("SELECT `".implode('`,`',$fields)."` FROM `{$table}` WHERE `{$where}` IN(".implode(',',$ids).")")->result_array();
    
    $data = array();
    foreach($res as $k=>$v)$data[$v[$where]] = $v;#数据对接
    
    foreach($r as $k=>$v){
        foreach($fields as $val){
            $r[$k][$pre.$val] = $data[$v[$in]][$val];
        }
    }
    return $r;
}