为什么链接到查询数据库不起作用？

Question

我有一个显示链接的页面，所以当我点击该链接时，它应该带我到另一个页面并查询数据库，以便我只能看到特定链接的信息。但现在它给了我一个问题，它是我在其他程序中使用的相同代码。我一直试图弄清楚这个问题差不多2个小时。请在下面列出任何可以帮助你的人的代码。

First piece of code or page 
<?php 
$selector1 =("SELECT job_id, job_title, job_description, 
job_category, wantORoffering, address, cell, email, date_registered, 
user_id from h2s_job ORDER BY date_registered DESC LIMIT $offset, $rowsperpage"); 
$result_selector=$con->prepare($selector1); 
$result_selector->execute(); 
while($row = $result_selector->fetch(PDO::FETCH_ASSOC)){ 
#substring 
$job_description = $row['job_description']; 
$job_description = wordwrap($job_description , 200); 
$job_description = explode("\n", $job_description); 
$job_description = $job_description [0] . '...'; 
#substring 
echo '<a href="jobdetails.php?job_id=$job_id"><div id="record" id ="record-"> 
<strong class="pic"><img src="images/nopic.png" ></strong> 
<strong class="job_title"><h4>',$row['job_title'],'</h4></strong></br> 
<strong class ="desc"><p>',$job_description,'</p></strong></br> 
    <strong class="contact"><p>',$row['cell'],'</strong></br> 
<strong class="time"><p>',$row['date_registered'],'</strong></br> 
</div></a>'; 
}?> 



Second page 


<?php 

$selector =("SELECT job_title, job_description, 
job_category, wantORoffering, address, cell, email, date_registered, 
user_id FROM h2s_job WHERE job_id =".$_GET['job_id']); 
$result_selector=$con->prepare($selector); 
$result_selector->execute(); 
while($row = $result_selector->fetch(PDO::FETCH_ASSOC)){ 
#substring 
$job_description = $row['job_description']; 
echo '<div id="record" id ="record-"> 
<strong class="pic"><img src="images/nopic.png" ></strong> 
<strong class="job_title"><h4>',$row['job_title'],'</h4></strong></br> 
<strong class ="desc"><p>',$job_description,'</p></strong></br> 
    <strong class="contact"><p>',$row['cell'],'</strong></br> 
<strong class="time"><p>',$row['date_registered'],'</strong></br> 
</div></a>'; 
} 
?> 

我得到

Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[42S22]: Column not found: 1054 Unknown column '$job_id' in 'where clause'' in C:\wamp\www\houseCurrent\jobdetails.php:98 Stack trace: #0 C:\wamp\www\houseCurrent\jobdetails.php(98): PDOStatement->execute() #1 {main} thrown in C:\wamp\www\houseCurrent\jobdetails.php on line 98 

Answer 1

概率你忘了在第一while

Answer 2

$ JOB_ID添加$job_id = $row['job_id'];似乎并没有被定义的错误，并与回声声明ISN创建的链接'你想要什么（我希望...）Option1没有分配job_id的实际值（它分配字符串'$ job_id'）。

选项2的伎俩，并分配到的job_id值5

<?php 
$job_id = 5; //example 

//OPTION 1 This would output to html => jobdetails.php?job_id=$job_id 
echo '<a href="jobdetails.php?job_id=$job_id">test</a>'; 

//OPTION 2 This would output to html => jobdetails.php?job_id=5 
echo '<a href="jobdetails.php?job_id=' . $job_id . '">test</a>'; 
?> 

你可以改变...（选项1）

echo '<a href="jobdetails.php?job_id=$job_id"><div id="record" id ="record-"> 
<strong class="pic"><img src="images/nopic.png" ></strong> 
<strong class="job_title"><h4>',$row['job_title'],'</h4></strong></br> 
<strong class ="desc"><p>',$job_description,'</p></strong></br> 
    <strong class="contact"><p>',$row['cell'],'</strong></br> 
<strong class="time"><p>',$row['date_registered'],'</strong></br> 
</div></a>'; 

到（选项2）

echo '<a href="jobdetails.php?job_id=' . $job_id . '"><div id="record" id ="record-"> 
<strong class="pic"><img src="images/nopic.png" ></strong> 
<strong class="job_title"><h4>' . $row['job_title'] . '</h4></strong></br> 
<strong class ="desc"><p>' . $job_description . '</p></strong></br> 
    <strong class="contact"><p>' . $row['cell'] . '</strong></br> 
<strong class="time"><p>' . $row['date_registered'] . '</strong></br> 
</div></a>'; 

逗号已被句点替换，因为。用于串联字符串。