Why my mysql transaction is not working properly? - php

Question

I've been reading and gathering information for 2 days already and I give up. I have no clue why my piece of simple code is not succeeding.
I want to insert data from one form into two tables and YES I know there are exactly same problems described here and there, but as I said I'm familiar with them and also need to ask more questions.
The problem is in my query somewhere, at least this is what I believe it is.
Here it goes:
unset($err);
//Variables
$host = 'my.server.com';
$user = '123';
$pass = 'password';
$dbname = '123';
$err = array();
$error_form = false;
$img = "sth/sth.jpg";
//Connecting to the database using mysqli application programming interface
$con = mysqli_connect($host, $user, $pass, $dbname);
if (!validate()) {
if (!$con) {
echo "Connection failed : <br />" . $new_con->connect_errno . "<br />" . $new_con->connect_error;
exit;
} else {
echo "Connected! <br />";
}
var_dump($name);
echo "<br />";
var_dump($email);
echo "<br />";
var_dump($img);
echo "<br />";
$query= "START TRANSACTION;
INSERT INTO `123`.`table1` (`name1`,`name2`)
VALUES ('". $name . "','". $email ."');
INSERT INTO `123`.`table2` (`table1_id`,`name3`,`name4`)
VALUES (LAST_INSERT_ID(),'". $story . "','". $img ."');
COMMIT;";
var_dump(mysqli_query($con,$query));
echo "<br />";
$_POST["name"] = "";
$_POST["email"] = "";
$_POST["story"] = "";
}
//Form validation
function validate() {
global $name, $email, $story, $err, $error_form;
if($_SERVER['REQUEST_METHOD']=="POST") {
if(isset($_POST["name"]) && !empty($_POST["name"])) {
$name = htmlspecialchars($_POST["name"]);
} else {
$err[0] = "Name is missing.";
$error_form = true;
}
if(isset($_POST["email"]) && !empty($_POST["email"])) {
if (filter_var($_POST["email"], FILTER_VALIDATE_EMAIL)) {
$email = htmlspecialchars($_POST["email"]);
} else {
$err[1] = "Email was verified as incorrect.";
$error_form = true;
}
} else {
$err[1] = "Email is missing.";
$error_form = true;
}
if(isset($_POST["story"]) && !empty($_POST["story"])) {
$story = htmlspecialchars($_POST["story"]);
} else {
$err[2] = "Your story does not contain any characters, it can't be submited.";
$error_form = true;
}
}
return $error_form;
}
Everything what confuses me happens here:
$query= "START TRANSACTION;
INSERT INTO `123`.`table1` (`name1`,`name2`)
VALUES ('". $name . "','". $email ."');
INSERT INTO `123`.`table2` (`table1_id`,`name3`,`name4`)
VALUES (LAST_INSERT_ID(),'". $story . "','". $img ."');
COMMIT;";
var_dump(mysqli_query($con,$query));
I've tried to SELECT the id FROM the table1 table and SET it as a #value instead of LAST_INSERT_ID(). I've tried to run two queries...many different solutions.
I found out when I dump mysqli_query($con,$query) it gives false every time unless I don't use transaction, so just simple queries, but I need them.
Last thing is should I use PDO instead of mysqli? Why?
and
Why to use mysqli object oriented style instead of procedural one?
Every help is appreciated. I would like more to understand than just to achieve the effect here.
Be aware this is my first post here, but not the first visit.

Answer 1

You can only do one query at a time with mysqli_query Look at mysqli_multi_query()
http://www.w3schools.com/php/func_mysqli_multi_query.asp
$query= "START TRANSACTION;
INSERT INTO `123`.`table1` (`name1`,`name2`)
VALUES ('". $name . "','". $email ."');
INSERT INTO `123`.`table2` (`table1_id`,`name3`,`name4`)
VALUES (LAST_INSERT_ID(),'". $story . "','". $img ."');
COMMIT;";
var_dump(mysqli_multi_query($con,$query));