Update a custom column value sql - php

Question

When outside the boxing thinking. I came up with the following solution:
$column = 'product';
$enum = '1';
$product_access = $dbh->prepare("UPDATE products_access SET {$column} = :enum WHERE products_access.id = :id");
$product_accessvar = trim($user['id']);
$product_access->bindParam(':id', $product_accessvar, PDO::PARAM_INT);
$product_access->bindParam(':enum', $enum, PDO::PARAM_INT);
//$product_access->bindParam(':product_enum', $enum);
//foreach($_POST["checkbox2"] as $loc_id)
$product_access->execute();
Thanks for your help, maybe i can help someone with my solution. It works for me now!
Below my question
I have a question about my follow project. I build an sql table where the users can add custom columns with a enum value. But the user can also update the value of this column. I can't set any column name because they all custom made by the user, so there is no column name.
My SQL:
tabel `products_access`
--
CREATE TABLE IF NOT EXISTS `products_access` (
`id` int(30) NOT NULL,
`user_id` int(30) NOT NULL,
`product 2` enum('0','1') NOT NULL COMMENT 'Dit is een product beschrijving van product 2.dgfdg'
)
Array:
Array
(
[id] => 17
[name] => product 2
[number] => 2002
[description] => Dit is een product beschrijving van product 2.
[mount] => 34
[price] => 6778
[deleted] => 0
[user_id] => 17
[product 2] => 1
)
Script:
<label>
<input name="clickedproduct[]" type="checkbox" value="<?php echo $avlue['id']; ?>" <?php echo (($_SERVER['REQUEST_METHOD'] == 'POST') ? ((isset($_POST[$avlue['name']])) ? ' value="'.$avlue[$avlue['name']].'" checked' : ' value="'.$avlue[$avlue['name']].'"') : (($avlue[$avlue['name']] == '1') ? ' value="'.$avlue[$avlue['name']].'"checked' : ' value="'.$avlue[$avlue['name']].'"')); ?>>
<?php echo $avlue['name']; ?>
</label>
PDO:
$product_access = $dbh->prepare('UPDATE products_access() VALUES(:id, :loc)');
$product_access->bindValue(':id', $id);
$product_access->bindParam(':loc', $loc_id);
foreach($_POST["checkbox2"] as $loc_id) $product_access->execute();
Below the array after saving.
Array
(
[username] => joshua
[rank] => Array
(
[0] => 0
)
[koppel] => Array
(
[0] => 1
)
[clickedproduct] => Array
(
[0] => 17
)
)
Can some one explain the solution?

Answer 1

This sort of application ordinarily is implemented using a metadata table, also known as a key / value store.
Each row of this metadata table identifies
the object it describes, with a product_id or similar foreign key.
the name of the data item it holds, e.g. 'price' or 'mount'
the value of the data item it holds, e,g, '6778' or '34'
optionally a code identifying the data type of the item ('money'? 'text'?)
It's easy to add metadata to an object. Insert a row into the metadata table giving the "column name" you want and the value. It's a little trickier to retrieve it. You need a query, for example, like this.
SELECT p.product_id, a.val as price, b.val as mount
FROM product p
LEFT JOIN metadata a ON a.product_id = p.product_id AND a.key='price'
LEFT JOIN metadata b ON b.product_id = p.product_id AND b.key='mount'
WordPress's wp_postmeta table setup is a good and widely used example of this data design pattern. It has a workable API.
It's ordinarily considered bad practice to use data definition language commands (like ALTER TABLE CHANGE colname newcolname INT) in production. For one thing these commands are quite slow and thread-unsafe. For another, when a schema contains all kinds of user-defined columns it's hard to troubleshoot. You're better off using application code, like what I have suggested here, to allow your users to create their own data keys and values.

Answer 2

Create a column named 'custom_column' in 'products_access'.(Add user
defined column name here)
Create another table named 'tbl_custom_column'
Add fields 'user_id', 'custom_column_value' (Add your values here)
Hope that will help.