如何在PDO中使用mysql_data_seek? [英] how use mysql_data_seek with PDO?

问题描述

我想将mysql_data_seek与来自Google搜索的PDO一起使用，我发现它看起来应该像这样:

I want use mysql_data_seek with PDO from google search I found that it should looks like this:

$row0 = $result->fetch(PDO::FETCH_ASSOC, PDO::FETCH_ORI_ABS, 0);

无论如何，我做错了什么? 这是我的代码:

however it's not work, what I do wrong? this is my code:

$query = "SELECT name,age FROM users";
$q = $db->prepare($query);
$q->execute();

$q->setFetchMode(PDO::FETCH_ASSOC);
$arrayData = $q->fetchAll();

foreach ($arrayData as $row){

    echo $row['name'] ." ";
    echo $row['age'] ."<br>";
}

$result = $q->fetch(PDO::FETCH_OBJ,PDO::FETCH_ORI_ABS,4);
var_dump($result);

我只想从上一次运行的查询中以对象形式获得第5行.我不想再次运行此查询(就像有些人告诉我的那样)，我只想要sql缓冲区的结果.

I just want get the 5th row in object form from the last run query. I don't want run this query again (as some guys told me) I just want the results from sql buffer.

var_dump结果为:bool(false)

the var_dump result is: bool(false)

有什么想法吗?

感谢您的回答，对不起，但也许我也无法解释自己.我喜欢JSON的技巧，但要点是第五行是示例.我只希望使用与PDO完全相同的缓冲区查询结果，就像我在常规mysql中使用mysql_data_seek所做的一样(更改游标).是否有可能?我喜欢所有的花招，但不是我想要的.

thanks for your answers and sorry but maybe I don't explain myself as well. I like the trick with JSON but the point is that the 5th row is example. I just want use the result of the query from the buffer with PDO exactly as I did it with mysql_data_seek in regular mysql (change the cursor). is it possible? I like all the tricks but that not what I look for.

推荐答案

PDO'cursor'的默认值为 PDO :: CURSOR_FWDONLY ，这意味着游标无法像mysql_data_seek那样回到零.要允许光标归零，必须定义可滚动光标"

the PDO 'cursor' default is PDO::CURSOR_FWDONLY that means that cursor can't back to zero like it happens with mysql_data_seek to allow cursor back to zero it necessary define use 'scrollable cursor'

示例:

$db->prepare($query, array(PDO::ATTR_CURSOR => PDO::CURSOR_SCROLL));

在像这样使用之前:

$row0 = $result->fetch(PDO::FETCH_ASSOC, PDO::FETCH_ORI_ABS, 0);

这篇关于如何在PDO中使用mysql_data_seek?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！