How to display posts of a specific category onclick of menus?

[yateesh]

I have two tables , Post and Category .

Post

pid title result content cid
1 Option1 Opt content1 2
2 Option2 Opt content2 2
3 Option3 Opt content3 3

Category

cid cname
1 Cat 1
2 Cat 2
3 Cat 3

This is my insert.php

mysql_connect('localhost','root','');

mysql_select_db("database") or die("Unable to select database");

$title=$_POST['post_title'];
$result=$_POST['post_result'];
$content=$_POST['post_content'];
$sid=$_POST['cid'];
$date=$_POST['date'];

$insertquery="INSERT INTO review (post_title,post_result,post_content,cid,date)
          VALUES('$title','$result','$content',$sid,NOW())";


$result=mysql_query($insertquery);

if(! $result )
{
  die('Could not enter data: ' . mysql_error());
}
else {

        echo "Entered data successfully\n";
        header('Location:home.php');
    }

This is my cat.php which displays posts of particular category.

$link = mysql_connect("localhost","root","");
mysql_select_db("database");

$query="SELECT * FROM category WHERE cid='$cid'";

 $result = mysql_query($query) or die("Query to get data failed with error:  ".mysql_error());

while($row = mysql_num_rows($result)) { 
echo    //details goes here

}

This is my category menu list on home page .

<ul>            
<li><a class="my-button" href="#">Cat 1</a></li>
<li><a class="my-button" href="#">Cat 2</a></li>
<li><a class="my-button" href="#">Cat 3</a></li>
</ul>

This is javascript.

<script>
$(document).ready(function() {
$('body').on('click', '.my-button', function() {

   $("#display").load("cat.php");

   });
});
</script>

Everything is getting inserted to database correctly . But im not able to display the posts of specific category onclick .

I have given the complete code . What i want is , when i click on Cat 1 or Cat 2 or Cat 3 on home page , i need to display all data from post table of the selected category in #display div .

I am getting an error saying , cid is undefined variable .

Do tell me anything else to be added or it would be better if you write the required code for me .

Thank you.

[Rabbit]

In your cat.php, you never define what $cid is supposed to be.

[yateesh]

Okay. How do i go about that ?

[Anas Mosaad]

You second snippet, the fourth line may need to be something like this:

$query="SELECT * FROM category WHERE cid='" . $cid . "'";

[yateesh]

That is not working..

[Rabbit]

That won't work because you still need to tell it what $cid is supposed to be. Basically, if I just came up to you and ask you, "What is x?" There's no way for you to answer that question unless I told you "x = 5" at some point. That's what you're trying to do with your code. You're telling the code to use $cid without you ever telling it what $cid is supposed to be.

One way of defining $cid would be to do this:

$cid = 1;

That hard codes the value 1 to the variable $cid. How you define it is dependent on your requirements. Meaning I can't help you with it unless you tell me what it's supposed to be.

[Anas Mosaad]

Currently, you are loading the same page without identifying which category you are querying. You may add an id to each menu item and add action handler for each one to load the page with the required parameter.

<ul>            
<li><a class="my-button" id="cat1" href="#">Cat 1</a></li>
<li><a class="my-button" id="cat2" href="#">Cat 2</a></li>
<li><a class="my-button" id="cat3" href="#">Cat 3</a></li>
</ul>

JavaScript handlers cat1 menu item:

$('body').on('click', '#cat1', function() {
   $("#display").load("cat.php?cid=Cat%201");
   });
});

You need to repeat the above code for all the categories.

Finally read the request parameter in your cat.php page.

$cid = $_GET["cid"]

One more thing, your page is vulnerable to SQL injection attack. You should encode/escape the parameters in order to close this security hole.

[yateesh]

@Rabbit
When i click on categories , it should take the id or category name ( not sure which one ) of the selected category and match its id with the table and retrieve the posts related to that particular category . I can't specify cid=1 or cid=2 becoz it needs to take the value of the selected category name .

[Rabbit]

I know you can't. That was just an example to show you where you went wrong. You just need to code it to your requirements. Anyways, Anas has answered specifically to your situation.

[yateesh]

This is my updated statements in cat.php

$cid = $_GET["cid"];

$query="SELECT pid,post_title,post_result,post_content,date FROM review WHERE cid=$cid";

$result = mysql_query($query) or die("Query to get data failed with error: ".mysql_error());

while($row = mysql_num_rows($result)) {
//details 
}

This is the script . What should i put in place of ?? .

<script>
$(document).ready(function() {
     $('body').on('click', '#cat1', function() {
	 
    $("#display").load("cat.php?cid=[B]??[/B]");
	
  });
});
</script>

If i put 1 in place of ?? , nothing is getting displayed and no error message also .

[yateesh]

@Anas Mosaad
$("#display").l oad("cat.php?ci d=Cat%201"); here what should i put in place of Cat%201 . What does it actually mean .

[adi501]

in 1st table give cid as primary key,and 2nd table cid as foreign key ,and use join condition

[adi501]

SELECT * FROM post
INNER JOIN category
ON post.cid=category.cid

u can use where condition also.

[yateesh]

@adi501
In javascript $("#display").l oad("cat.php?ci d=Cat%201"); here what should i put in place of Cat%201
I need to pass cid value to server right , so what should i give there .

[yateesh]

@adi501
Nothing is getting displayed from below code :

$("#display").load("cat.php?cid=[B][I]cid%1[/I][/B]");

$cid = $_GET["cid"];

$query="SELECT * FROM review
INNER JOIN category
ON review.cid=category.cid WHERE review.cid='$cid'";