Better solution for sequential statement executions with PDO and PHP - php

Question

I have 3 tables which I have to add a record to them after registration of a new user:
List of Tables:
I. users
... ... ... id (auto_increment, primary)
... ... ... email (email address of new user)
II. blogs
... ... ... id (auto_increment, primary)
... ... ... owner_id (= 'id' in 'users')
III. events
... ... ... id (auto_increment, primary)
... ... ... owner_id (= 'id' in 'users')
... ... ... blog_id (= 'id' in 'blogs')
In this situation I found 2 solutions for adding sequential records:
Solution 1: Using lastInsertId
<?php
try {
// Step 1: add a record to 'users' table and get lastInsertId
$query = $conn->prepare("INSERT INTO users (email) VALUES (:email)");
$query->bindParam(':email', $email);
$query->execute();
$user_id = $conn->lastInsertId();
// Step 2: add a record to 'blogs' table and get lastInsertId
$query = $conn->prepare("INSERT INTO blogs (owner_id) VALUES (:owner)");
$query->bindParam(':owner', $user_id);
$query->execute();
$blog_id = $conn->lastInsertId();
// Step 3: add a record to 'events' table
$query = $conn->prepare("INSERT INTO events (owner_id, blog_id) VALUES (:owner, :blog)");
$query->bindParam(':owner', $user_id);
$query->bindParam(':blog', $blog_id);
$query->execute();
} catch (PDOException $e) {
echo $e->getMessage();
}
?>
Solution 2: Using single execute()
<?php
try {
// Step 1
$query = $conn->prepare("INSERT INTO users (email) VALUES (:email);" .
"INSERT INTO blogs (owner_id) VALUES ((SELECT id FROM users WHERE email = :email));" .
"INSERT INTO events (owner_id, blog_id) VALUES ((SELECT id FROM users WHERE email = :email), (SELECT id FROM blogs WHERE owner_id = (SELECT id FROM users WHERE email = :email)));");
$query->bindParam(':email', $email);
$query->execute();
} catch (PDOException $e) {
echo $e->getMessage();
}
?>
Which solution should I choose for a better performance and security? Is there a better solution for my purpose?
Note: the connection created using PDO:
<?php
$options = array(
PDO::MYSQL_ATTR_INIT_COMMAND => 'SET NAMES utf8',
);
try {
$conn = new PDO("mysql:host=" . App::DB_HOST . ";dbname=" . App::DB_NAME . ";charset=utf8", App::DB_USERNAME, App::DB_PASSWORD, $options);
} catch (PDOException $e) {
echo $e->getMessage();
}
?>

Answer 1

I would use transactions as a modification of 1st option.
$conn->beginTransaction();
try {
// Step 1: add a record to 'users' table and get lastInsertId
$query = $conn->prepare("INSERT INTO users (email) VALUES (:email)");
$query->bindParam(':email', $email);
$query->execute();
$user_id = $conn->lastInsertId();
// Step 2: add a record to 'blogs' table and get lastInsertId
$query = $conn->prepare("INSERT INTO blogs (owner_id) VALUES (:owner)");
$query->bindParam(':owner', $user_id);
$query->execute();
$blog_id = $conn->lastInsertId();
// Step 3: add a record to 'events' table
$query = $conn->prepare("INSERT INTO events (owner_id, blog_id) VALUES (:owner, :blog)");
$query->bindParam(':owner', $user_id);
$query->bindParam(':blog', $blog_id);
$query->execute();
$conn->commit();
}
catch (PDOException $e) {
// roll back transaction
$conn->rollback();
echo $e->getMessage();
die();
}

Answer 2

If you do some benchmarks you will see most time will be lost making the request.
From personal benchmarks on simple queries like this the execution time is very low.
The only thing that realy took time is the initialisation/prepare function.
There for making 3 requests will be slower then creating one large one.
EDIT:
Option 1 is the correct one because you do need to use id's, never link using a string or somethign else allways use id's.
Appart from that 1 (prepared) big query is better then 3x a prepare.

Answer 3

Edit. I misread the question at first, thought you are using exec(), not execute().
So, in fact you can combine both, as lastInsertId is just a PHP wrapper for Mysql's LAST_INSERT_ID()
But, as you need two ids, it will require additional mess with setting a variable. So, I doubt second option would worth, although feasible.
Just note that second would work only if PDO emulation mode is turned off
And surely there is no such question like "performance". Both will go perfectly.