Dear programmers, I need your assistance with the following code:

$select_table = $this->query("SELECT title FROM dct")->fetchAll();
       
foreach($select_table as $key) {
    $k[] = $key['title'];
    $d[] = [':'.$key['title'] => $form[$key['title']].','];
}
$l = implode(',',$k);
$ls = implode(', :', $k);

$this->query('INSERT INTO dc_m (name,'.$l.', pruef, file_id) VALUES (:name, :'.$ls.', :pruef, :file_id)', [
    ':name'=>$form['name'],
    $d.':pruef'=> 1,
    ':file_id' => $file_id
]);
I receive an error message when executing the insert into statement: SQLSTATE[HY094]: Invalid parameter number: parameter was not defined. Can you please advise me on how to resolve this issue?

To provide some context, I have a table and employees can add rows to it. Based on this table, I need to add data to another table. The name passed from $_POST corresponds to the name of the title column.

The dct table contains the titles of the columns in the dc_m table. The dct table is updated dynamically, and its titles correspond to the columns of the dc_m table.

When adding data, an array of $_POST is passed, which includes all parameters that match the dct table's title column data. I need to output all dct titles dynamically, assign them to $_POST, and add them all to the dc_m table.

To clarify, can employees modify the fields of another table by adding rows? If so, you may not need to store a separate list of fields in another table. Instead, you can retrieve the list of fields directly from the table by selecting * from the table with any condition, even an empty selection.

In case you need to use custom column names, you can utilize column comments. Comments are supported in both MySQL and PGSQL.

Alternatively, you can perform all operations using a single table. Simply generate the lists as usual - a list of field names, a list of parameter names, and a list of field values (parameters) as an array.

Using unnamed parameters could potentially simplify the process.

let's analyze the problematic parts of your original code:

$select_table = $this->query("SELECT title FROM dct")->fetchAll();
     
foreach($select_table as $key) {
    $k[] = $key['title'];
    $d[] = [':'.$key['title'] => $form[$key['title']].','];
}
$l = implode(',' ,$k);
$ls = implode(', :', $k);

$this->query('INSERT INTO dc_m (name,'.$l.', pruef, file_id) VALUES (:name, :'.$ls.', :pruef, :file_id)', [
    ':name'=>$form['name'],
    $d.':pruef'=> 1,
    ':file_id' => $file_id
]);

Now, let's address the issues and provide a detailed explanation of the corrections:

1. Building the Parameter Array: In the foreach loop, you are constructing the `$d` array by adding an array for each title. Instead, we need to directly create key-value pairs in the `$d` array, with the title as the key and the form value as the value. This array will be used for binding the parameters in the query.

2. Constructing the Query and Parameter Binding: We need to ensure that the query is built dynamically based on the column names fetched from the `dct` table. Additionally, we should construct an array of parameters to be bound to the query, including the form values, `pruef`, and `file_id`.

Here's the detailed correction code with thorough explanation:

// Fetch the titles from the dct table
$select_table = $this->query("SELECT title FROM dct")->fetchAll();

// Initialize arrays for column names and parameter bindings
$columnNames = [];
$bindValueArray = [];

// Construct the column names and parameter bindings dynamically
foreach ($select_table as $key) {
    $columnNames[] = $key['title']; // Collecting column names
    $bindValueArray[':' . $key['title']] = $form[$key['title']]; // Binding parameters
}

// Construct the query string
$columns = implode(',', $columnNames);
$placeholders = implode(', :', $columnNames);
$query = 'INSERT INTO dc_m (name,' . $columns . ', pruef, file_id) VALUES (:name, :' . $placeholders . ', :pruef, :file_id)';

// Add form data, pruef, and file_id to the parameter binding array
$bindValueArray = array_merge($bindValueArray, [
    ':name' => $form['name'],
    ':pruef' => 1,
    ':file_id' => $file_id
]);

// Execute the query with bound parameters
$this->query($query, $bindValueArray);

In this corrected version, we dynamically construct the column names, parameter placeholders, query string, and parameter binding array based on the data fetched from the `dct` table. This approach allows for flexible insertion of data into the `dc_m` table based on the dynamic nature of the column names. Additionally, we ensure that the form data, `pruef`, and `file_id` are properly included in the parameter binding array to execute the insert query successfully.

By addressing these issues and implementing the detailed corrections, the code should now function as intended, effectively mapping the form data to the dynamic column names and performing the insertion into the `dc_m` table.