在while循环中运行时的进度条 [英] Progress bar while running while loop

问题描述

我有一个while循环，它基本上循环遍历数据库中的许多记录，并将数据插入另一个数据库中:

I have this while loop, that basically loops through a lot of records in a database, and inserts the data in another:

$q = $con1->query($users1) or die(print_r($con2->errorInfo(),1));
while($row = $q->fetch(PDO::FETCH_ASSOC)){
    $q = $con2->prepare($users2);
    $q->execute(array($row['id'], $row['username'])) or die(print_r($con2-errorInfo(),1));
}

(该脚本已缩短，易于阅读-正确的脚本具有更长的数组)

我想做更多的图形化操作，并显示进度条，而不是仅仅看到几分钟的页面加载(此行有〜20.000行-我的表有很多更多数据)

I would like to do this more graphical, and show a progress bar on how far it has went, instead of just seeing a page loading for a few minutes (there are ~20.000 rows in this one - I have tables with much more data)

我知道您可以从旧数据库中获得总数，并且我也可以轻松地将当前数字放入这样的变量中:

I get that you could get the total number from the old database, and I could also easily put the current number into a variable like this:

$q = $con1->query($users1) or die(print_r($con2->errorInfo(),1));
$i = 0;
while($row = $q->fetch(PDO::FETCH_ASSOC)){
    $q = $con2->prepare($users2);
    $q->execute(array($row['id'], $row['username'])) or die(print_r($con2-errorInfo(),1));
    $i++;
}

但是现在我需要实际获取$i并显示它-或类似的东西.

But now I need to actually fetch $i and display it - or something like it.

如何轻松"完成?

进度条的代码可以与while循环位于同一文档中，如果方便，也可以位于另一文档中.

The code for the progress bar can either be in the same document as the while loop, or in another if easier.

推荐答案

您可以执行一个"master"文件，该文件对此第一个文件进行ajax运算以运行单个查询.您可以在此主文件中获取所有条目ID，然后将其作为参数传递给执行单个查询的第二个文件.将这些ID存储在javascript数组中.

You can do a "master" file that does an ajax to this first file to run a single query. You could get all the entry id's in this master file, and then pass it as a parameter to the second file that does a single query. Store these ids in a javascript array.

创建一个执行此操作的函数，完成第一个ajax时，移至id数组的第二个元素，并使用第二个参数执行另一个ajax.这就是magento导入的方式:)

Create a function that does this, and when the first ajax is done, move to the second element of the id array, and do another ajax with a second parameter. That's how magento imports are done by the way :)

如果您需要进一步的说明，请告诉我，我已尽力解释，但可能还不够清楚.

If you need further explanations, let me know, I tried my best to explain, but may have not been perfectly clear.

// you generate this javascript array using php.
// let's say you have all the ids that have to be processed in $Ids php array.
Ids = [<?php echo implode(',', $Ids); ?>];

function doAjax(i) {
    $.ajax({  // using jquery for simplicity
        'url': "ajax.php?id=" + Ids[i],
    }).done(function(){
        if ( i >= 0 ) {
            // at the point you know you're at ((Ids.length-i)/(Ids.length) * 100) percent of the script
            // so you can do something like this:
            // $('.progressbar').css('width', ((Ids.length-i)/(Ids.length) * 100) + '%');
            doAjax(i-1);
        }
    });
}

doAjax(Ids.length); // starting from the last entry

因此，仅解释一下它的作用.首先声明一个全局javascript数组，其中包含所有需要更改的ID.

So, just to explain what this does. It starts by declaring a global javascript array that has all the ids that will need to be changed.

然后，我声明一个递归ajax函数，这样我们可以确保在任何一次都只运行一个ajax(这样服务器就不会崩溃)，并且可以取得相当准确的进度.此ajax函数执行以下操作:

Then I declare a recursive ajax function, this way we can make sure that only one ajax runs at any single time (so the server doesn't blow up), and we can have a fairly accurate progress. This ajax function does the following:

• 向ajax.php?id = xxx发送请求-其中xxx是javascript数组中的ID之一.
• 在文件中，我们获得ID($_GET['id'])，将其从旧数据库中取出，然后将其插入新数据库中.这仅适用于一个条目.
• 完成ajax后，它将转到done()函数.由于我们从最后一个元素开始doAjax()函数，因此我们进行了下一个迭代doAjax(i-1).由于我们要在数组中向后移动，因此我们检查键是否为正.如果不是，脚本将停止.

• Sends a request to ajax.php?id=xxx - where xxx is one of the ids in the javascript array.
• In the file, we get the id ($_GET['id']), you take it from the old database, and insert it in the new one. This is only for one entry.
• when the ajax is done, it goes to the done() function. Since we start the doAjax() function with the last element, we do the next iteration doAjax(i-1). Since we're going backwards in the array, we check if the key is positive. If it's not, the script will stop.

就是这样.

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