如何检查是否选中了复选框，并执行必要的查询以更新相应的表？

Question

HTML

<label for="wall_category">Wall Category:</label>
    <input type="checkbox" name="wallpaper"> Wallpaper
    <input type="checkbox" name="photography"> Photography

PHP

//obtains last insert id
    $wallId = mysql_insert_id();
    echo $wallId;

I have categories table in my database in which the following data is stored:

category_id  category_name
1             Wallpaper
2             Photography

and I have another table called wall_categories in which:

wall_id (P, F)    category_id (P, F)

After getting the wall_id from last_insert_id, I want to check what category among the two is checked. For example, Wallpaper checkbox is checked, since the category_id is 1, I want to store that category_id along with whatever the wall_id will be to my wall_categories table. So my table will become (lets say wall_id is 16)

wall_id (P, F)    category_id (P, F)
 16                 1

And one last thing to add since Categories are checkboxes, when both are selected, I want to add both to my wall_categories table so my wall_categories table would become:

wall_id (P, F)    category_id (P, F)
     16                 1
     16                 2

I was trying some workarounds, but I'm still a rookie in PHP. Would like to ask your help on how to do this. Thanks! (The script will just be used internally.)

Answer 1

HTML

<form action="process.php" method="POST">
    <label for="category">Wall Category:</label>
    <input type="checkbox" name="category[]" value="1"> Wallpaper
    <input type="checkbox" name="category[]" value="2"> Photography
</form>

If you want to proceed checkboxes input, i suggest you to do it as the script above. category[] would be an array that could contain values such as 1 and 2 (your category id).
So you have to parse it in server side(PHP) before you insert it into database. if you set the wall_id column value automatically generated you will get some errors, because wall_id would be different with previous wall_id. So i suggest you to set it automatic but manually defined(didn't get my words? I'll explain it).
Here's the PHP :

<?php
$con = mysqli_connect("host","username","password","database_name");
//First get the category from input
$checked = $_REQUEST['category']; // it's an array

//--------get last
    //Then you have to get the last wall_id from your wall_categories table
    //and add it 1 (+1)
    $q1 = mysqli_query($con,"SELECT MAX(wall_id) as last_wall_id from wall_categories"); // get last wall_id
    $last = mysqli_fetch_array($q1);
    $next_wall_id = $last['last_wall_id']+1;//+1 last wall_id for next wall_id
//-------end of get last

foreach($checked as $cat){
mysqli_query($con,"INSERT INTO wall_categories (wall_id, category_id) values ('$next_wall_id','$cat') ");
}
?>

If your wall_id comes from another table, please skip get last step. and remove/change the $next_wall_id by the wall_id variable that you get from another table.
That's all if you want to do it. Any question? found some errors? comment it below :D