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Who am I A Dutchy in Kiwiland October 12th, 2016 • Wellington • Simon Erkelens ● Hello, my name is Simon ● I’m a software developer ● I work for SilverStripe ● Ninja Unicorns ● Twitter: @Firesphere ● GitHub: https://github.com/firesphere ● These slides will be on https://speakerdeck.com/firesphere ● Dutch ● I have a cat! (Her name is Sylvester Marika) ● You know it’s me, when you see Hans ● Don’t bother trying to pronounce my surname ● I’m not anti-social. Just not user-friendly Hans, my RDD tool. She’s a cow Little miss Sylvester/Marika

Notes in advance Because I had to make some relational things October 12th, 2016 • Wellington • Simon Erkelens ● I am trying to explain ORM, therefore, I had to add some weird things that either require mapping, or not? ● I’m assuming you all have a working copy of the StripeGirls website, so you can code along, or write some code yourself ● If you don’t, ask for help getting it set up correctly. We’re here to help and learn ● I have a Dutch accent. Sorry, can’t do much about that ● This is a bit technical. If you don’t understand, don’t be afraid to ask ● I have a whole set of images I often use in presentations. If you’ve seen one of my presentations before, you might recognise some of them

A dive into (SilverStripe) ORM October 12th, 2016 • Wellington • Simon Erkelens Because humans are developers too https://twitter.com/Una/status/743382603210891264

ORM Object Relational Mapping October 12th, 2016 • Wellington • Simon Erkelens ● What is ORM? ● Object Oriented ● Relational ● Mapping ● ORM is not Database! ● ORM applies Relational logic to given information ○ It does not have to come from the database! (Although it often does) ● The relational logic is defined by the Mapping given or created ● The mapping is defined in the Object itself

DRY Why use an ORM? October 12th, 2016 • Wellington • Simon Erkelens ● Don’t ● Don’t again ● Repeat ● Repeat again ● Yourself ● Yourself again ● How not to do it ● Stuff it all in a single object ● Stuff everything in a single object

So, what’s the big deal? Object Relational Mapping October 12th, 2016 • Wellington • Simon Erkelens ● Efficiency ● Reusability ● Readability ● Independently readable ● Applicable to other objects if needed ● Neatly grouped (in the database) ● Object Oriented ● Relational ● Mappings The opposite of DRY is not as compelling in real life

How not to do it Please don’t do this? October 12th, 2016 • Wellington • Simon Erkelens class StripeGirl extends DataObject { private static $db = array( 'Name' => 'Varchar(255)', 'Email' => 'Varchar(255)', 'Address' => 'Text', ); }

The only thing worse is serialisation Serialising user input is like opening your backend to the world. October 12th, 2016 • Wellington • Simon Erkelens https://www.owasp.org/images/8/8c/RemoteCodeExecutionInWordPress-OW ASPBeNeLux-Tom_Van_Goethem.pdf Yep, serialisation is that bad.

Better…. (Sorry, couldn’t get it bigger on screen) October 12th, 2016 • Wellington • Simon Erkelens Did I say “RELATIONAL” already? Spot the error class StripeGirl extends DataObject { private static $db = array( 'Name' => 'Varchar(255)', 'Email' => 'Varchar(255)', 'Relationship' => 'Varchar(255)', 'Street' => 'Varchar(255)', 'Number' => 'Int', 'Area' => 'Varchar(255)', 'City' => 'Varchar(255)', 'Country' => 'Varchar(255)', 'MailingStreet' => 'Varchar(255)', 'MailingNumber' => 'Int', 'MailingArea' => 'Varchar(255)', 'MailingCity' => 'Varchar(255)', 'MailingCountry' => 'Varchar(255)', 'HomePhone' => 'Varchar(15)', 'WorkPhone' => 'Varchar(15)', 'MobilePhone' => 'Varchar(15)', );

Almost, but what about relations? I mean…. “RELATIONAL” is part of ORM October 12th, 2016 • Wellington • Simon Erkelens ● Indeed, relations are missing => thus, no option to get M for Mapping yet ● What can be made into a relation in the previous object declaration ● Address? ● Phone numbers? ● Relationship status? ● What about Gender? ● Or country? ○ I might be over-abstracting here Unicorns are awesome by the way

So, what relations to apply Relations are awesome (usually) October 12th, 2016 • Wellington • Simon Erkelens ● People live at the same place ● Phone numbers aren’t groupable ● Relationship status is (a) t(h)ough (one) ● And first names are ● Speed versus reusability

So, what relations to apply Relations are awesome (usually) October 12th, 2016 • Wellington • Simon Erkelens ● People live at the same place ● Some of you have roommates, right? ● Phone numbers aren’t groupable ● Relationship status is (a) t(h)ough (one) ● And first names are ● Speed versus reusability

So, what relations to apply Relations are awesome (usually) October 12th, 2016 • Wellington • Simon Erkelens ● People live at the same place ● Some of you have roommates, right? ● Phone numbers aren’t groupable ● Relationship status is (a) t(h)ough (one) ○ But is it sensible? ● And first names are ● Speed versus reusability

So, what relations to apply Relations are awesome (usually) October 12th, 2016 • Wellington • Simon Erkelens ● People live at the same place ● Some of you have roommates, right? ● Phone numbers aren’t groupable ● Relationship status is (a) t(h)ough (one) ○ But is it sensible? ● And first names are ○ Do you think that’s sensible? ● Speed versus reusability

So, what relations to apply Relations are awesome (usually) October 12th, 2016 • Wellington • Simon Erkelens ● People live at the same place ● Some of you have roommates, right? ● Phone numbers aren’t groupable ● Relationship status is (a) t(h)ough (one) ○ But is it sensible? ● And first names are ○ Do you think that’s sensible? ● Speed versus reusability ● Yes, it will add another database query sometimes ● Easier to use in other places in your code ○ Unless you over-abstract

Setup a logical structure Because an ORM based system, relies on logic October 12th, 2016 • Wellington • Simon Erkelens ● Draw it out. What makes sense and what doesn’t ○ You can do this in your head usually, but sometimes drawing it out for real helps! ● Define shareable properties ● A person has an address which can be shared ● A person has a name which can’t be shared ● A relationship status is personal, but there aren’t much. What’s smart here? ● A country is a personal part of the Address

Setup a logical structure Because an ORM based system, relies on logic October 12th, 2016 • Wellington • Simon Erkelens ● Draw it out. What makes sense and what doesn’t ● Define shareable properties ● A person has an address which can be shared ○ That’s a useful thing. That’s Object Oriented thinking ● A person has a name which can’t be shared ● A relationship status is personal, but there aren’t much. What’s smart here? ● A country is a personal part of the Address

Setup a logical structure Because an ORM based system, relies on logic October 12th, 2016 • Wellington • Simon Erkelens ● Draw it out. What makes sense and what doesn’t ● Define shareable properties ● A person has an address which can be shared ○ That’s a useful thing. That’s Object Oriented thinking ● A person has a name which can’t be shared ○ So, even though there might be 10 people named Annie, it’s still unique to the person ● A relationship status is personal, but there aren’t much. What’s smart here? ● A country is a personal part of the Address

Setup a logical structure Because an ORM based system, relies on logic October 12th, 2016 • Wellington • Simon Erkelens ● Draw it out. What makes sense and what doesn’t ● Define shareable properties ● A person has an address which can be shared ○ That’s a useful thing. That’s Object Oriented thinking ● A person has a name which can’t be shared ○ So, even though there might be 10 people named Annie, it’s still unique to the person ● A relationship status is personal, but there aren’t much. What’s smart here? ○ Enumeration instead of a new Object is a good idea for these things ● A country is a personal part of the Address

Setup a logical structure Because an ORM based system, relies on logic October 12th, 2016 • Wellington • Simon Erkelens ● Draw it out. What makes sense and what doesn’t ● Define shareable properties ● A person has an address which can be shared ○ That’s a useful thing. That’s Object Oriented thinking ● A person has a name which can’t be shared ○ So, even though there might be 10 people named Annie, it’s still unique to the person ● A relationship status is personal, but there aren’t much. What’s smart here? ○ Enumeration instead of a new Object is a good idea for these things ● A country is a personal part of the Address ○ Except if you want to have additional information, e.g. used currency, as part of the country

October 12th, 2016 • Wellington • Simon Erkelens Credits to Randall Munroe, creator of XKCD This is XKCD 1134 Logic Boat! Or a cabbage, for that matter. The goat makes sense. Goats are fine.

But it’s still not ORM Mapping! October 12th, 2016 • Wellington • Simon Erkelens ● Now, there’s an Object Oriented, Relational approach ● But in the end, it’s about Mapping ● Map an address to another object ● Map a relationship status to a set of defaults ○ Or not? It completely depends on the situation ● Map a country to an address I was told to add kittens to my presentations. So, here’s the kitten.

What about “mapping” Map map map map map October 12th, 2016 • Wellington • Simon Erkelens ● A map is a logical pointer to a shared object, instead of duplicating ● It keeps all your objects tidy and readable ● Your code is Object Oriented and logically structured ● This pointer is indexed when the entire relation is saved into a database

What about “mapping” Map map map map map October 12th, 2016 • Wellington • Simon Erkelens ● A map is a logical pointer to a shared object, instead of duplicating ● It’s like saying “this person’s address is in the Address database, at point X” ○ And the address points to a country with more information about the country ● It keeps all your objects tidy and readable ● Your code is Object Oriented and logically structured ● This pointer is indexed when the entire relation is saved into a database

Wait, you said “Indexed” A little sidetrack here October 12th, 2016 • Wellington • Simon Erkelens ● Indexes are like a link on a webpage, they (almost) instantly resolve to the mapped object ● An index is a quick way to search inside the database ● Indexes speed up your database queries a lot ● Indexes are key to what the Mapping is when data is stored in the database ● If you are interested in indexes and how they help, I need to refer you to my friend Philipp Krenn. He’s a database genius. ● https://vimeo.com/144108480

Mapping in SilverStripe Map map map map map October 12th, 2016 • Wellington • Simon Erkelens ● Relations ● has_one ● belongs_to ● has_many ● many_many ● belongs_many_many ● Don’t think yourself, let the framework do the mapping ● Understand what a mapping means in your code ● When doing $StripeGirl->Address(); You’re addressing the ORM

Mapping in SilverStripe Map map map map map October 12th, 2016 • Wellington • Simon Erkelens ● Relations ● has_one ● belongs_to ● has_many ● many_many ● belongs_many_many ● Don’t think yourself, let the framework do the mapping ● Understand what a mapping means in your code ● Preferably, before you dive in and make mistakes ● When doing $StripeGirl->Address(); You’re addressing the ORM

Mapping in SilverStripe Map map map map map October 12th, 2016 • Wellington • Simon Erkelens ● Relations ● has_one ● belongs_to ● has_many ● many_many ● belongs_many_many ● Don’t think yourself, let the framework do the mapping ● Understand what a mapping means in your code ● Preferably, before you dive in and make mistakes ● When doing $StripeGirl->Address(); You’re addressing the ORM ● The SilverStripe ORM will find the StripeGirl::AddressID and fetch the related address, based on the AddressID, returning an Address object ● Or, in SilverStripe Templating engine, you can use <% with $Address %>

What makes SilverStripe better? There’s no perfect solution. October 12th, 2016 • Wellington • Simon Erkelens ● The mapping maps. What else do you want? ● The easy way to quickly setup your mapping configuration ● The static naming is clear, you can’t go wrong ● You don’t have to use additional code to create the mapping yourself

What makes SilverStripe better? There’s no perfect solution. But Stripey McMapface is quite nice! October 12th, 2016 • Wellington • Simon Erkelens ● The mapping maps. What else do you want? ● The easy way to quickly setup your mapping configuration ● The static naming is clear, you can’t go wrong ● You don’t have to use additional code to create the mapping yourself ● For example, but not limited to: ○ Annotations ○ YML ○ XML (oh god no!)

Thank you! @Firesphere https://github.com/Firesphere [email protected] https://speakerdeck.com/firesphere https://casa-laguna.net October 12th, 2016 • Wellington • Simon Erkelens