How to Dynamically Bind Parameters with `bind_param()` When Handling Empty Values in PHP?

Dynamic Variable Binding with bind_param()

When working with variable numbers of input variables for bind_param(), handling empty values can be a challenge. Attempting to use "..." in the placeholder string may not be feasible due to empty $_POST values.

A solution to this problem is to use call_user_func_array() to pass a variable number of arguments to the bind_param() method:

<code class="php">$parameterNames = array('myvar1', 'myvar2', /* ... */);
$parameters = array();
foreach ($parameterNames as $name) {
    if (isset($_POST[$name]) && $_POST[$name] != '') {
        $parameters[$name] = $_POST[$name];
    }
}

if (count($parameters)) {
    $query = 'UPDATE mytable SET ';
    foreach ($parameters as $name => $value) {
        $query .= $name.'=?,';
    }
    $query = substr($query, 0, -1); // Remove trailing comma
    $query .= 'WHERE id = ?';

    $statement = $mysqli->prepare($query);
    $typeString = str_repeat('s', count($parameters));
    $parameters = array_merge(array($typeString), array_values($parameters));
    call_user_func_array(array($statement, 'bind_param'), $parameters);
}</code>

This approach allows you to dynamically generate the SQL query based on the available $_POST values, ensuring that only non-empty values are included in the update statement.

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