php页面无响应

I am not sure which part caused the page response nothing.These page is host in my lubuntu machine. However, when I access this page from another LAN computer,choosing the startDate to be '2012-12-16' and endDate to be '2013-12-16', the page just freeze in Chrome browser. Any idea when it is freeze? When I call $.get('duty.php'... , the alert even cannot pop up. When I going stright to

/attendence/duty.php?mode=9&startDate=2012-12-06&endDate=2013-12-06&christened=All

the return is

[]

*EDIT 2 * Found the reason and it turns out to be another "silly" question.The problem was caused by $.get(). As you can see the output from php is an empty array [] ,which is ok. Yet the $.get() function did not see it as a valid response and just wait until the browser timeout.(Using jQuery 1.7.2) The workaround is to return json with some content like {'no','result'}.

Apache2 access.log

192.168.1.7 - - [06/Dec/2012:21:02:48 +0800] "GET /attendence/duty.php?mode=9&startDate=2012-12-06&endDate=2013-12-06&christened=All HTTP/1.1" 500 411 "-" "Mozilla/5.0 (X11; Linux i686) AppleWebKit/535.19 (KHTML, like Gecko) Ubuntu/11.10 Chromium/18.0.1025.168 Chrome/18.0.1025.168 Safari/535.19"

$.get('duty.php',
{'mode':9,
    'startDate':$('input[name=startDate]').val(),
    'endDate':$('input[name=endDate]').val(),
    'christened':$('input[name=christened]:checked').val()},
    function(data, textStatus, jqXHR){
         alert('result reach back');
        if (typeof data === 'undefined') {
         return;
        }
        numWeek = getDiffWeek();
        tableHtml='Num Of week：'+numWeek+'<table border=1><tr>';
        tableHtml+='<td>Barcode</td><td>name</td><td>attendence</td><td>frequency</td>';
        tableHtml+='    </tr></table>';
        $('#attendenceRate').html(tableHtml);
        for(name in data){

            attendenceRate = Math.round(data[name]['times']/numWeek*100);
            memberIcon ='';

            $('#attendenceRate table').append('<tr><td>'+data[name]['barcode']+'</td><td>'+name+'</td><td>'+attendenceRate+'%</td><td>'+data[name]['times']+'</td></tr>');

        }
    }
    ,'json'
    );

EDIT just a typo, should be duty.php instead of Duty.php

include ("lock.php");
if($_GET){
if ($_GET['mode']==9){//calculate overall christian attendence
    $startDate = $_GET['startDate'];
    $endDate = $_GET['endDate'];
    $christened=$_GET['christened'];
    if($christened=='All'){
        $christenedClause='';
    }else{
        $christenedClause= ' AND record.christened = '.$christened;
    }

    $sql = <<<EOD
    SELECT name,barcode, COUNT( * ) AS times ,christened,gender
    FROM (

    SELECT name,attendence.barcode as barcode, DATE, TIME,christened,gender
    FROM attendence, record
    WHERE attendence.barcode = record.barcode
    AND DATE
    BETWEEN  "$startDate"
    AND  "$endDate"
    $christenedClause
    GROUP BY name, DATE

    )A
    GROUP BY name

EOD;

    $result = $link->query($sql);
    $data = array();
    $i=0;
    if($result->num_rows>0){

        while ($result2 = $result->fetch_assoc()){

            $data[$result2['name']]['times'] = $result2['times'];
            $data[$result2['name']]['barcode'] = $result2['barcode'];
            $data[$result2['name']]['gender'] = $result2['gender'];
            $data[$result2['name']]['christened'] = $result2['christened'];
            $i++;

        }
    }
    echo json_encode($data); 
}
}

Your page is throwing a Server Error. The 500 in your access log (All HTTP/1.1" 500 411) means that the page couldn't load. You need to fix something in your PHP page.

First, I would not use the .get() command and instead use the .ajax() command. The .ajax() command includes methods to abort on failure (.fail()) and to stop trying after a set amount of time (timeout:).

$.ajax({
    url: url,
    type: "GET",
    timeout: 1000,
    data: { 'mode':9,
        'startDate':$('input[name=startDate]').val(),
        'endDate':$('input[name=endDate]').val(),
        'christened':$('input[name=christened]:checked').val()
     }
}).done(function(data) {
    alert('success!');
    //  ...
}).fail(function(jqXHR, textStatus, errorThrown) {
    alert('fail :(');
    //  ...
});

Second, your SQL can be cleaned up. As @Shivan pointed out, many of the words in your query (e.g.: date, time, record) are Keywords: words that are used as functions or datatypes. MySQL gets confused if you try to use one of these words as a column name, so you need to escape it with the backtick (`) character.

I've also put the dates inside of single quotes (')

SELECT 
    `name`, `barcode` , COUNT( * ) AS `times`, `christened`, `gender`
FROM (
    SELECT 
        `name`, attendence.barcode as `barcode`, `DATE`, `TIME`, `christened`, `gender`
    FROM 
        `attendence`, `record`
    WHERE
        `attendence`.`barcode` = `record`.`barcode`
        AND `DATE`
        BETWEEN  '$startDate'
            AND  '$endDate'
        $christenedClause
    GROUP BY `name`, `DATE`
)A
GROUP BY name

I don't think that this will fix all of your problems, so you should enable error reporting on your PHP page. Put this code at the top of duty.php:

ini_set('display_errors',1); 
error_reporting(E_ALL);

If this works right, then PHP will display error messages instead of just failing.

Add whatever something in the $data array so that it won't return an empty json. At the end of duty.php add

...
if( count($data)==0){
$data['content']=['none'];
}
echo json_encode($data);