Cannot create and import answers without an image for an quiz

[pro2s]

Hi, I encountered the problem that I can't save answers to questions in a quiz that doesn't contain an image, and later when exporting and importing such answers, they are not imported.
It seems for my database using an empty string instead of null in 'image_id' does not allow saving the answer to database.
I had to patch the plugin to be able to use the null value in Image ID.
If the plans are fixed it this or is it possible to somehow use answers without images for MariaDB without changing the plugin?

There are patches:

diff --git a/helpers/QueryHelper.php b/helpers/QueryHelper.php
--- a/helpers/QueryHelper.php
+++ b/helpers/QueryHelper.php
@@ -174,7 +174,11 @@
 				if ( $sanitize_value && $do_sanitize ) {
 					$sanitize_value = sanitize_text_field( $sanitize_value );
 				}
-				$column_values .= is_numeric( $sanitize_value ) ? $sanitize_value . ',' : "'$sanitize_value'" . ',';
+				$column_values .= match( true ) {
+					is_null( $sanitize_value ) => 'NULL,',
+					is_numeric( $sanitize_value ) => $sanitize_value . ',',
+					default => "'$sanitize_value',",
+				};
 			// Trim trailing comma.
 			$column_keys   = rtrim( $column_keys, ',' );

diff --git a/classes/QuizBuilder.php b/classes/QuizBuilder.php
--- a/classes/QuizBuilder.php
+++ b/classes/QuizBuilder.php
@@ -98,7 +98,7 @@
                        'belongs_question_type' => $question_type,
                        'answer_title'          => $answer_title,
                        'is_correct'            => $is_correct,
-                       'image_id'              => $image_id,
+                       'image_id'              => empty ( $image_id ) ? null : $image_id,
                        'answer_two_gap_match'  => $answer_two_gap_match,
                        'answer_view_format'    => $answer_view_format,
                        'answer_settings'       => $answer_settings,
```

```
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```