PHP transaction processing data implementation code_PHP tutorial

public function insertUser ($userArray){
foreach ($userArray as $key => $value) {
@$field .= "$key,";
@$content .= "'$value',";
}
$field = ereg_replace(',$' , '', $field);
$content = ereg_replace(',$', '', $content);

$db = db_connect(); //Connect to the database

$db->autocommit(FALSE); //Set to non-automatic commit - transaction processing

$sql1 = "INSERT INTO t_user (".$field.") VALUES (".$content. ")";
$result1 = $db->query($sql1);

$sql2 = "INSERT INTO t_userpost (f_username) VALUES ('".$userArray['f_username']. "')";
$result2 = $db->query($sql2);

if ($result1 && $result2) {
$db->commit(); / /All successful, submit the execution result
echo 'Submit';
} else {
$db->rollback(); //If any error occurs, roll back and cancel the execution result
echo 'Rollback';
}
$db->close();
}