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我的问题是我有一个很大的数据库(10000+ 行)并且想用 php 和 mysqli 一次得到它们。但是当我用 var_dump 打印所有结果时,我只得到第一行。就像那是唯一发生的事情。所以我的问题是:php mysql 连接有限制吗?还是我的代码中有错误。

这是我的代码:

$link = mysqli_connect("localhost","root","","ows_index2");
$info_wu = mysqli_query($link,"SELECT `hostname`, `page` from `pages`");
$row = mysqli_fetch_assoc($info_wu);
var_dump $row;

(带有php括号,登录很好,因为我得到了第一行)

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3 回答 3

2

这是您的代码中的错误。

这个:

$row = mysqli_fetch_assoc($info_wu);
var_dump($row);

应该:

while($row = mysqli_fetch_assoc($info_wu))
    var_dump($row);
于 2012-04-15T22:31:32.950 回答
2

如果你有 PHP 5.3+,你可以使用新的mysqli_fetch_all()代替 mysqli_fetch_assoc()。

$rows = mysqli_fetch_all($info_wu, MYSQLI_ASSOC);

var_dump($rows);
于 2012-04-15T22:41:42.730 回答
1

mysqli_fetch_assoc一次只取一行。并且没有任何东西可以使用mysqliAFAIK 获取所有行(不是完整的 mysqli pro)。(编辑:

我建议你把它变成一个迭代器,然后像数组一样使用这个迭代器:

/**
 * Iterator that fetches each iteration value from a
 * function until it is not string and equals false.
 */
class FetchIterator extends NoRewindIterator
{
    /**
     * @var string
     */
    private $fetchCallback;
    /**
     * number of the current iteration
     * @var int
     */
    private $virtual;
    /**
     * cache of the current value
     * @var mixed
     */
    private $current;

    /**
     * @param string $fetchCallback
     */
    public function __construct($fetchCallback)
    {
        $this->fetchCallback = $fetchCallback;
        $this->virtual = 0;
    }

    /**
     * Return the current element
     * @link http://php.net/manual/en/iterator.current.php
     * @return mixed Can return any type.
     */
    public function current()
    {
        $this->virtual || $this->next();
        return $this->current;
    }

    /**
     * Return the key of the current element
     * @link http://php.net/manual/en/iterator.key.php
     * @return scalar scalar on success, integer
     * 0 on failure.
     */
    public function key()
    {
        $this->virtual || $this->next();
        return $this->virtual - 1;
    }

    /**
     * Checks if current position is valid
     * @link http://php.net/manual/en/iterator.valid.php
     * @return boolean The return value will be casted to boolean and then evaluated.
     * Returns true on success or false on failure.
     */
    public function valid()
    {
        $this->virtual || $this->next();
        return $this->validate();
    }

    /**
     * @return bool
     */
    private function validate()
    {
        return FALSE != $this->current || is_string($this->current);
    }

    /**
     * Move forward to next element
     * @link http://php.net/manual/en/iterator.next.php
     * @return void Any returned value is ignored.
     */
    public function next()
    {
        if ($this->virtual && ! $this->validate()) {
            return;
        }
        $this->fetch();
        $this->virtual++;
    }

    /**
     * fetch value from callback. can be called
     * after assigning a new callback while
     * in iteration.
     */
    public function fetch()
    {
        $func = $this->fetchCallback;
        $this->current = $func();
    }

    /**
     * number of times the fetch callback function
     * has been called so far.
     *
     * @return int
     */
    public function getCallCount()
    {
        return $this->virtual;
    }

    /**
     * @return callback
     */
    public function getFetchCallback()
    {
        return $this->fetchCallback;
    }

    /**
     * Set callback for subsequent iterations.
     *
     * @param callback $fetchCallback
     * @return FetchIterator
     */
    public function setFetchCallback($fetchCallback)
    {
        $this->fetchCallback = $fetchCallback;
        return $this;
    }
}

用法:

$info_wu = mysqli_query($link,"SELECT `hostname`, `page` from `pages`");
$fetchFunction = function() use ($info_wu) {
    return mysqli_fetch_assoc($info_wu);
}
$it = new FetchIterator($fetchFunction);
$rows = iterator_to_array($it);

变量$rows现在是一个数组,每个元素包含一行。而不是iterator_to_array您也可以使用foreach并自行处理每一行。

迭代器代码对于您的情况可能看起来有点过多,它是一种更通用的代码,可用于数据库结果操作的许多情况。一篇相关的博客文章是:Some PHP Iterator Fun,展示了如何多次迭代同一个迭代器。

于 2012-04-15T22:42:51.513 回答