make the dropdown field unique

ff_unique_dropdown.php

add_filter('fluentform_validate_input_item_select', function ($errorMessage, $field, $formData, $fields, $form) {
    
	$fieldName       = 'dropdown'; //name attribute of the dropdown field

	$target_form_id  = 597; //change the form id

	if($target_form_id !=  $form->id){ return $errorMessage; }
   	
	
	if ($inputValue = \FluentForm\Framework\Helpers\ArrayHelper::get($formData, $fieldName)) {
		$exist = wpFluent()->table('fluentform_entry_details')
			->where('form_id', $form->id)
			->where('field_name', $fieldName)
			->where('field_value', $inputValue)
			->first();
	
		if ($exist) {
			 $errorMessage = "Error ! This field needs to be unique.";
			 return [$errorMessage];
		}
	}
   	
    return $errorMessage;

}, 10, 5);