无论如何，是否有必要检查php mysql中“ SELECT…INTO OUTFILE”的执行时间（已用或剩余）？

Question

I am writing a query, which fetches many millions of rows from a table and puts in to a txt file. 我正在写一个查询，该查询从表中提取数百万行并将其放入txt文件。

$sQuery  = " ( ";
        $sQuery .= " SELECT number ";
        $sQuery .= " INTO OUTFILE '".$outputfile_dnd."' ";
        $sQuery .= " FIELDS TERMINATED BY ','  ";   
        $sQuery .= " LINES TERMINATED BY '\r\n' ";
        $sQuery .= " FROM `".$database."`.$temp_table_name";
        $sQuery .= " WHERE number IN (SELECT number FROM `db_dnd`.`dnd` )";
        $sQuery .= ")";

Since there will be huge data, this will take several minutes of time to complete sometimes. 由于将有大量数据，因此有时需要几分钟的时间才能完成。 I want to make the users to know how much more time the process will run(roughly). 我想让用户知道该过程将运行多少时间（大约）。 I am thinking to keep a button in frontend, when user clicks the button, it should show the time remaining. 我想在前端保留一个按钮，当用户单击该按钮时，它应该显示剩余时间。 If its not possible to findout remaining time, If i can get the elapsed time and number of rows selected,then also its fine. 如果无法找出剩余时间，如果我可以获取经过的时间和所选的行数，那么也可以。 Any help? 有什么帮助吗？ Worst case I am thinking to go with INSERT IN TO other table then put to file after everything is inserted. 最糟糕的情况是我想将INSERT IN TO插入其他表，然后在插入所有内容后将其保存到文件中。

Answer 1

You can run an ajax request to the php script when the user presses the button. 当用户按下按钮时，可以向php脚本运行ajax请求。 Then you can count in Javascript, the time until you get a response from the ajax file. 然后，您可以使用Javascript计数，即从ajax文件获得响应之前的时间。

To get the time elapsed in php you can do (the following assumes you are using mysqli): 要获取经过php的时间，您可以执行以下操作（以下假设您正在使用mysqli）：

$startTime = microtime();
$result = $mysqli->query($sQuery); #This is your function that runs the actual query
$endTime= microtime(true);
$timeTaken= $endTime- $startTime;

To get the number of rows (in mysqli) you can just grab it off of the result object. 要获取行数（在mysqli中），您可以从结果对象中获取它。

$numRows = $result->num_rows;

Edit for Js ajax version : 编辑Js ajax版本：

So if you have Jquery on your frontend the following would work. 因此，如果前端有Jquery，则可以使用以下方法。 So this involves separating all of your php that runs and displays the query into a separate file. 因此，这涉及将运行并显示查询的所有php分离到一个单独的文件中。 Then call the URL of that file below and it will show how long has elapsed before the output of said file. 然后在下面调用该文件的URL，它将显示在输出该文件之前已经经过了多长时间。

<script src="https://code.jquery.com/jquery-3.1.1.min.js" integrity="sha256-hVVnYaiADRTO2PzUGmuLJr8BLUSjGIZsDYGmIJLv2b8=" crossorigin="anonymous"></script>
<script type="text/javascript">
$(document).ready(function(){
    var startTime = new Date().getTime();
    var requestInterval = window.setInterval(function() {
        $("#content_area").html("Time Elapsed :"+(new Date().getTime() - startTime) / 1000+" Seconds");
    }, 500);
    jQuery.get('URLofYOURScriptHERE', 
        function(data, status, xhr) {
            clearInterval(requestInterval)
            var timeTaken = new Date().getTime() - startTime;
            $("#content_area").html(data);
        }
    );
});
</script>
<body>
<div id="content_area">
</div>
</body>

无论如何，是否有必要检查php mysql中“ SELECT…INTO OUTFILE”的执行时间（已用或剩余）？

问题描述

1 个解决方案

解决方案1
1 已采纳 2017-02-14 11:15:01

无论如何，是否有必要检查php mysql中“ SELECT…INTO OUTFILE”的执行时间（已用或剩余）？

问题描述

1 个解决方案

解决方案1 1 已采纳 2017-02-14 11:15:01

解决方案1
1 已采纳 2017-02-14 11:15:01