Workaround for nested while->fetch - php

Question

Good day everyone!
Currently I'm trying to find a workaround for my problem. As fair as I am concerned, MySqli doesnt support nested fetch'es, therefore my function doesn't quite work. I've tried to find a fix, but had no luck. My current code:
function viewQuestionnaire($id){
$questionStmt = $this->connection->prepare("SELECT id, type, name FROM TAP_questions WHERE questionnaire_id=?;");
$questionStmt->bind_param("i", $id);
$questionStmt->bind_result($id, $type, $name);
$questionStmt->execute();
$result = array();
while ($questionStmt->fetch()) {
$questions = new StdClass();
$questions->question_id = $id;
$questions->question_type = $type;
$questions->question_options = array();
$questions->question_name = $name;
if($questions->question_type=="2"){
$stmtOptions= $this->connection->prepare("SELECT id, options FROM TAP_options WHERE question_id=?;");
$stmtOptions->bind_param("i", $id);
$stmtOptions->bind_result($qu_id, $qu_opt);
$stmtOptions->execute();
while ($stmtOptions->fetch()) {
$options = new StdClass();
$options->option_id = $qu_id;
$options->option_name = $qu_opt;
array_push($questions->question_options, $options);
}
$stmtOptions->close();
}
array_push($result, $questions);
}
$questionStmt->close();
return $result;
}
As you can see, i'm trying to grab values from database, depending on the question type. If the question type is "2", i need to grab "additional" values from another table. How do i do that?
Vlad

Answer 1

I had more or less exactly this problem two weeks ago and found two working solutions:
1.) Nesting the queries, but using/initializing two different connections for them (even if it's to the same database)
2.) Doing one query first, saving the result in an array and using that array later inside the other query.

Answer 2

If you buffer the result, you can run the second query w/o loosing the result from the first query.
In Mysqli you buffer the result of an executed prepared statement (which by default is unbuffered) via the mysqli_stmt::store_result method.
...
$questionStmt = $connection->prepare(
"SELECT id, type, name FROM TAP_questions WHERE questionnaire_id=?;"
);
$questionStmt->bind_param("i", $id);
$questionStmt->bind_result($id, $type, $name);
$questionStmt->execute();
/* store result */
$questionStmt->store_result();
...
/* free result */
$questionStmt->free_result();
$questionStmt->close();
...