我需要保留mysqli_query（）和mysqli_close（）吗？

Question

Do I still need to use mysqli_query($connection, $results); and mysqli_close($connection); ?

$sql = $connection->prepare("INSERT INTO pawnshop ".
    "(Pawnshop_Name, Street, Barangay, City, DTI_Permit_No, Mayor_Permit_No, Firstname, Middlename, Lastname, Contact_Number, Email_Address, Password) ".
    "VALUES ".
    "(?,?,?,?,?,?,?,?,?,?,?,?)");
    $sql->bind_param("ssssiissssss", $pawnshopName, $street, $barangay, $city, $dtiPermitNo, $mayorPermitNo, $firstName, $lastName, $middleName, $contactNumber, $email, $password);
    $sql->execute();
    $results = $sql->get_results();   
    mysqli_query($connection, $results);// Do I still need this?
    mysqli_close($connection); //Do I still need this

Answer 1

this much part of the code is enough for you to finish querying database.

$sql = $connection->prepare("INSERT INTO pawnshop ".
    "(Pawnshop_Name, Street, Barangay, City, DTI_Permit_No, Mayor_Permit_No, Firstname, Middlename, Lastname, Contact_Number, Email_Address, Password) ".
    "VALUES ".
    "(?,?,?,?,?,?,?,?,?,?,?,?)");
    $sql->bind_param("ssssiissssss", $pawnshopName, $street, $barangay, $city, $dtiPermitNo, $mayorPermitNo, $firstName, $lastName, $middleName, $contactNumber, $email, $password);
    $sql->execute();
    $results = $sql->get_results(); 

I see that you are mixing both OOP and Procedural Programming methods together by using mysqli_close($connection), it is not a good practice even though you can do it. Instead use method in $connection object like $connection->close();