Get all post from specific category with flexible code

Question

I have two table:

Table Post:

    id              cateid            content
   ####             ######        ###############
    14                35           Lorem isplum

Category table:

    id              name
   ####          #########
    35              Sport

I usually using method to get all post from category like this:

$itemSport = array();
$itemSport = getAllPostFromSportCate(35);

with 35 is values of table.

Problem is:

When I delete values 35 from Category table. I can't getAllPostFromSportCate($id) because Category table not exist this values.
I don't want insert values like 35 to function getAllPostFromSportCate($id). If user change id of Category table. All logic will fail.

Problem 2:

I don't want pass values like 35.

Normal, I receive values when user click button.

Like:

select * from Post where cateid = (select id from Category)

or

select * from Post where cateid = $_POST('idCate')

First problem: Just check if the `$id` exists before you try to find data from SQL. Second problem: As Nishant said, please explain more clearly. I don't understand what's your problem.. — Twinfriends, Jan 20 '17 at 08:49
Why are you hard coding `35`? You can have a Category selection (select box - where you show all available categories) and based on the selection you can filter records right? — masterFly, Jan 20 '17 at 08:53
@masterFly, in your case, user select a values available categories. If user not interactive with UI. — Ave, Jan 20 '17 at 09:01
Ok, then according to your logic from where you get the id `35`? — masterFly, Jan 20 '17 at 09:03
@masterFly I must open `phpMyadmin`, select the table `Category`, look all rows in this table to choose category correct with my conditional. I must hard code value `35` to my code. I don't want this. — Ave, Jan 20 '17 at 09:20
So what is you logic from start to end? Do you want to display posts for all available categories in the category table? — masterFly, Jan 20 '17 at 09:25

score 2 · Accepted Answer · edited May 23 '17 at 12:17

2

It looks like your question contains the answer (well, kind of):

select * from Post where cateid = $_POST('idCate')

You would build a form which lists the categories, that form could just use the ids of the categories as input values. Then the text shown for them would be the category name.

However, you need to make sure you properly escape the form values before you perform the database query, to prevent SQL injection

edited May 23 '17 at 12:17

Community

1
1

answered Jan 20 '17 at 09:07

aross

3,325
3
34
42

If I want get a array contain list Post with `cateid = 35`. In my question, I tried to example with user interactive with UI like select a `combobox` or click save button (event after click contain values). My case not like this. – Ave Jan 20 '17 at 09:13
@vanloc So you select based on category name? – aross Jan 20 '17 at 09:30

score 1 · Answer 2 · answered Jan 20 '17 at 08:47

1

Obviously you cannot get all the post from a category which their id has been deleted but you can check the category_id if it exists then get all the posts under it. I'm wondering, why would a user change the id of a category?

answered Jan 20 '17 at 08:47

aomanansala

90
9

score 0 · Answer 3 · answered Jan 20 '17 at 09:45

Dont let anyone delete a category. Let the user only change it.

$a_categories = array(1, 3, 4, 5, 9, ...); // get the existing ids from the database 

if($i_category AND in_array($i_category, $a_categories)){
 // your change of category code here
 // mysqli_query($link, "UPDATE posts SET cateid = ".$i_category." WHERE id = ".$i_postnumber);
}

No posts will be lost then

Get all post from specific category with flexible code

3 Answers3