Call to undefined function mysqli_begin_transaction() error - php

Question

I am using a php script that handles the backup & restore of my databases. There are several problems with it but I shall post 1 error at a time. When I click restore backup button I am getting the error in the title.
I am not experienced enough to troubleshoot this error and would appreciate some help from the experts. I have posted my code where the error occurs, but if you need to see anything else please let know. The error occurs at line 109. Thanks
PHP V5.3.13
MYSQL V5.5.24
APACHE V2.2.22
<?php
function restoredata($uploadedfile, &$ustartindex, &$uti, &$ulen, &$ucount, &$name, &$limit, $restoremethod)
{
global $host, $username, $passwd, $charset, $port, $upload_path, $backup_path;
$sql = '';
$zip = new ZipArchive();
$filename = $upload_path . '/' . $uploadedfile;
if (!is_file($filename)) {
$filename = $backup_path . '/' . $uploadedfile;
}
if ($zip->open($filename) !== TRUE) {
return "Cannot open file\n.";
}
try {
$dbName = $zip->getFromName('database.txt');
if ($restoremethod == '0') {
$conn = mysqli_connect($host, $username, $passwd, $dbName, $port);
}
else {
if ($uti == 0 && $ustartindex == 0) {
$conn = mysqli_connect($host, $username, $passwd, 'mysql', $port);
}
else {
$conn = mysqli_connect($host, $username, $passwd, $dbName, $port);
}
}
if (!$conn) {
return 'Could not connect ' . mysqli_error($conn);
}
if (!mysqli_set_charset($conn, $charset)) {
mysqli_query($conn, 'SET NAMES ' . $charset);
}
$tables = $zip->getFromName('tables.txt');
if ($tables === false) {
$zip->close();
return "Could'nt find tables";
}
$limit = intval($zip->getFromName('limit_info.txt'));
$tables = explode(',', $tables);
$ulen = count($tables);
if ($uti < $ulen) {
if ($uti == 0 && $ustartindex == 0) {
if ($restoremethod == '1') {
$sql = $zip->getFromName($dbName . '.sql');
if ($sql !== false) {
$sql = explode(';' . chr(10) , $sql);
for ($i = 0; $i < count($sql) - 1; $i++) {
$result = mysqli_query($conn, $sql[$i] . ';');
if (!$result) {
mysqli_close($conn);
$zip->close();
return 'Could not run query 1: ' . mysqli_error($conn);
}
}
}
mysqli_close($conn);
$conn = mysqli_connect($host, $username, $passwd, $dbName, $port);
if (!$conn) {
$zip->close();
return 'Could not connect ';
}
for ($i = 0; $i < $ulen; $i++) {
$name = $tables[$i];
$table = '`' . $name . '`';
$sql = $zip->getFromName($table . '.sql');
if ($sql !== false) {
$sql = explode(';' . chr(10) , $sql);
for ($j = 0; $j < count($sql) - 1; $j++) {
$result = mysqli_query($conn, $sql[$j] . ';');
if (!$result) {
mysqli_close($conn);
$zip->close();
return 'Could not run query 2: ' . mysqli_error($conn);
}
}
}
}
}
}
mysqli_autocommit($conn, FALSE);
// mysqli_begin_transaction ($conn, MYSQLI_TRANS_START_READ_ONLY );//READ ONLY transaction
mysqli_begin_transaction($conn, MYSQLI_TRANS_START_READ_WRITE); <---ERROR HERE
$name = $tables[$uti];
$table = '`' . $name . '`';
$ucount = intval($zip->getFromName($table . '.txt'));
$sql = $tables = $zip->getFromName($table . '/offset' . $ustartindex . '.sql');
$nerrors = 0;
$serrors = '';
if ($sql !== false) {
$sql = explode(';' . chr(10) , $sql);
for ($i = 0; $i < count($sql) - 1; $i++) {
$sql[$i] = str_replace('NULL', "''", $sql[$i]); //avoid NULL errors
$result = mysqli_query($conn, $sql[$i] . ';');
if (!$result) {
$serrors.= 'Could not run query in ' . $table . ' : ' . mysqli_error($conn) . '<br />';
$nerrors+= 1;
break;
}
}
$ustartindex+= $limit;
}
else {
$uti+= 1;
$ustartindex = 0;
}
if (!mysqli_commit($conn)) {
return "Transaction commit failed";
}
if ($nerrors > 0) {
mysqli_close($conn);
$zip->close();
return $serrors;
}
}
mysqli_close($conn);
$zip->close();
}
catch(Exception $e) {
return var_dump($e->getMessage());
}
return true;
}
?>
I will add that this is not my script but it does all all I need it to do including showing the progress of the backup, which visually is better than just a white page.
I would if possible like to sort these errors out and have a working script. Many thanks.

Answer 1

From http://php.net/manual/en/mysqli.begin-transaction.php, mysqli_begin_transaction is only supported from php 5.5.0 onwards. As your running 5.3 it won't work.
You could remove the transaction and it would work, especially as your originally trying to set a read-only transaction. Also remove the commit.
I would remove the following line as this would rely on transactions working as you'd expect.
mysqli_autocommit($conn, FALSE);
If you NEED to stay on 5.3 then...
mysqli_query($conn, "START TRANSACTION");