Create a one-to-many relationship: Users own multiple notes; note model handles the relationship, user model stays unaware. 

Learn how to establish one-to-many relationships between models in Prisma, including configuring relationship attributes and avoiding common pitfalls.

One-to-Many Relationships in Prisma

[00:00] Let's head over to our schema prisma file and right down here. We're going to create our note model So we'll say model note and this is going to have all the typical fields even copilot can fill this in for us So we've got our ID just like we have for our user model

[00:18] We have a title and content and then created at and updated out all of that pretty standard stuff And then we have our relationship. So let's talk about the relationship here. So we're going to call this relationship owner

[00:32] so when you have a note model or a note object you can access the owner by saying note dot owner and So this is going to reference the user model So that is named the same up there and then we define our relationship now copilot did its best But this is actually not the full relationship that we want. So

[00:51] The the syntax for this is the relation Attribute and then we provide these options for this attribute. So Yes, the relationship field that controls that relationship is the owner ID field and that is a string and that again is Going to be on the note model. We will make a change to the user model here in just a sec

[01:13] but the relationship is controlled by the note and Then it's Referencing the ID field of the owner. So if we go up here if we were to change this to User ID then down here. This would also be user ID So those two need to be the same, of course I'm not going to change that because that wouldn't make any sense

[01:32] So then finally we also want to have an on delete so that it cascades So if the user gets deleted we delete all their notes as well We don't want to have any notes that don't have owners. So that makes sense and on update the same story and then for

[01:50] The the reason that we're getting these red underlines is because we need to establish that Relationship on the user side of our model as well Even though in the database the user doesn't even know about the note You know our Prisma schema here to generate our client properly We do need to have some changes to our note model or to our user model as well

[02:10] So we're gonna need that. There we go And when I saved we have a VS code plugin that automatically Creates that relationship on the user side for some very unknown reason that I do not understand they capitalize the Property on the user model. And so what that actually would mean is

[02:31] If we're in a JavaScript file, we're going to have our user model that we got from Prisma and we're going to say yeah, it'd be Prisma user dot find first and If we also selected the note and here we have our user And yeah, it'd be oh wait There we go. So then we'd say user dot notes

[02:54] Yeah, or yeah, it's note. We want notes So what they autocompleted or or fixed for us is it be user dot note? And that would be an array of those note objects. I do not understand why they do it this way It doesn't make any sense. So we want it to be notes. And now this can be user dot notes

[03:14] That makes so much more sense. So be careful out there friends make sure that the you don't just blindly accept what the AI or your VS code extension is going to do maybe in the future AI will do all of this stuff for us But for right now AI and VS code plugins are not

[03:34] Something you just accept without review So quick review that this is it we're finished with this piece and so we've created our model ID title content created a updated app and then our owner relationship or our relationship with the user the field is going to be owner, so if I've got a await

[03:57] Prisma notes Find first or find many or whatever. We'll have our note and then that will be note dot user So that's or sorry, that'd be owner That is controlled by that property. So this actually is just kind of describing the relationship and

[04:17] Describing what property will be set on the note object. This is where we actually create a field in the database that will store the That primary key or that foreign key relationship So that is that now I think we also want to actually

[04:39] Do or push this change to our database, so let's grab the command for that we'll say NPX Prisma DB push and Boom, we've got that updated if I click this little plus now and oh here, you know what we might need to restart Prisma Studio and for that change, there we go and

[05:01] Now if I go to note then I can create a note if I want to so let's yeah Let's go ahead and do that Scooch this over add a record We're gonna say go ahead and make the ID for us We could actually customize that ourselves if we wanted to we can change it to whatever we want But I'm not going to do that we'll say the title is

[05:22] koalas are the best and No, really koalas rock Thank You Cody It's kind of a funny note to have because the owner of this note is going to be Cody So there we go And that will autofill our owner ID and so we can save that change and boom now

[05:44] We've got that and we can take a look at our database as well You could use the SQL lite 3 command or you can you just use the VS code extension and here? We'll see we've got that note in there as well. So Just

[05:59] Creating these one-to-many relationships. You just have to remember that the relationship is controlled by the ownee rather than the owner and and then you learn the syntax for how to make that happen in in Prisma and then make sure to

[06:17] That you're setting the properties to be the properties you want to access on the objects and that is one-to-many relationships in Prisma

One-to-Many Relationships 

[00:00] Now we're going to create our note model. So the note model is kind of interesting because it has a relationship with the user. So a single user can own multiple notes. And so we can make another note over here, and this note is owned by the user, and so on. The interesting thing here, though,

[00:18] is that we can't have a single note that's owned by multiple users. That's not allowed. So each user has their own note. And also what's interesting is in a one-to-many relationship like we have here, where one user can own many notes, you actually have the arrows actually backward.

[00:36] And so instead of having the user pointing to the note, the note actually points to the user like this. So the user actually will not have any reference to the note in the database. As far as the database is concerned, the user doesn't even know about the note.

[00:53] The note is the one that stores the information about that relationship. So the note is going to have a column for the owner ID, and then the user will just be there. In a Prisma schema, you do define a relationship in the model in the user.

[01:11] So you'll say what field you want the notes to be on that user model. But as far as the database is concerned, the note is the only one that knows about this one-to-many relationship. And so that's what you're going to be working on is adding this one-to-many relationship

[01:29] in our Prisma schema for these notes. And of course, you'll be also making the properties for the note itself as well. So have a good time with this, and we'll see you when you're done.

Data modeling is as a critical skill for the full stack developer. After all, data is the foundation of your application.

If you don't do it right, you'll find yourself stuck before you even get started. A poorly designed database schema can lead to a lot of headaches down the road when you need to make changes or add new features. Inefficient queries can slow down your application, leading to a poor user experience. Analyzing root causes to issues like these can be a time-consuming and frustrating process.

Web developers spend a ton of time into making their UI handle a slow backend well which is great and you should do that too (you don’t control network latency after all). But *****great***** web developers put effort into making it so their users hardly ever experience that great pending UI by making the backend as fast as possible. Your UI can’t be any faster than your slowest database query.

The Data Modeling Deep Dive Workshop will help you develop a keen understanding of databases and how to manage them. You'll learn the same tools and techniques used at the top tech companies to design robust database architectures and optimize query performance.

We'll be using production grade tools like Prisma and SQLite, but the concepts you learn in this workshop will be applicable to other database systems as well.

## Database Schema

A well-designed database schema is the foundation of your application. It's critical to get it right from the start, as it can be difficult to make changes down the road. This section provides a background on SQL before introducing Prisma's suite of tools. You'll learn:

- SQLite database initialization with Prisma
- Prisma's Object Relational Mapper (ORM)
- Defining a schema with Prisma's declarative schema language
- Converting a schema to SQL with the Prisma CLI
- Viewing and editing your database in Prisma Studio

## Relationships

Poorly planned relationships between database models can lead to data inconsistencies and increased query complexities and performance problems. To avoid these issues, you need to understand the different types of relationships and how to implement them. This section provides you with practical experience in recognizing relationships:

- One-to-many relationships (User has many Notes)
- One-to-one relationships (User has one UserImage)
- Updating the database with Prisma
- Planning models for the future
- Generate an Entity Relationship Diagram (ERD) for visualization

## Migrations

As your application evolves, so will your database schema. It's not uncommon for there to be "breaking changes" that affects one or more of your database models. This is where migrations come in.

Migrations allow you to track and synchronize schema changes across environments. Traditionally migrations have been tricky to manage, but this section will teach you how to use migrations to ensure your development, staging, and production environments are always in sync:

- Generating SQL migration code with Prisma
- Best practices for documenting & tracking migrations
- The "widen then narrow" approach for eliminating downtime
- Experimenting with migrations before permanently applying them

## Seeding Data

Manually adding data to a database is not only time-consuming but also prone to errors. Scripting to the rescue!

Here you'll learn how to populate your databases with consistent data for development and testing purposes:

- Initializing a SQLite database
- Idempotent scripting
- Resetting the database with Prisma
- Nesting SQL queries to simplify foreign key connections

## Generating Seed Data

Using hardcoded seed data works great for small applications, but it won't provide the best idea of how your application will perform at scale. You also shouldn't use real user data during development for plenty of obvious reasons.

A better approach is to use a library like Faker.js. This section will teach you how to use Faker.js to generate seed data for your database:

- Balancing realism with practicality when generating data
- Creating realistic user information
- Varying data quantities and randomness
- Validating against the schema
- Enforce data uniqueness

## Querying Data

In SQL, queries are written with the `SELECT` statement. This is one of the most powerful statements available, but it can also be one of the most complex. This is where tools like Object Relational Mappers (ORMs) come in, helping developers write SQL in a more intuitive way. Although it isn't a traditional ORM, the Prisma Client is an indispensable tool for modern web development. In this section, you'll learn how to get the most out of it:

- Understanding how Prisma's API maps to SQL
- Handling Hot Module Replacement (HMR)
- Logging slow queries
- Pre-connecting the client to the database

## Updating Data

Data mutation is a common task, but doing it incorrectly can lead to data corruption or loss. Especially when a single user action results in multiple database changes (for example, transferring money between user’s bank accounts). Getting mutations wrong can be a serious problem for your app’s success. This section will walk you through techniques for working safely:

- Deleting and updating data
- Conditional upserts
- Combining multiple queries into a transaction
- Rolling back to a previous transaction

## SQL

No matter how great an ORM is, sometimes you have to write raw SQL. In this section, you'll learn how to write raw SQL queries and execute them with Prisma. You'll also practice with:

- Wildcard queries
- Runtime schema validation with Zod
- Using joins to enable more complex queries
- Specifying query result ordering for more efficient searching

## Query Optimization

Nobody likes a slow application.

There are many stories of companies spending millions of dollars on scaling hardware, adding multiple levels of caching, and even rewriting their entire application in pursuit of a faster performance– only to find out later that the solution was optimizing their database indexes and queries.

In this final section, you'll learn how to optimize your queries for maximum performance:

- Identifying the index
- Analyzing raw SQL queries
- Multi-column indexing
- Balancing premature optimization with practicality

The Data Modeling Deep Dive Workshop will teach you best practices for designing database schemas, managing relationships, data mutations, and optimizations.

Data Modeling Deep Dive

Kent C. Dodds

Full Stack Vol 1

Intro to Data Modeling Deep Dive Workshop

Intro to Data Modeling Deep Dive

Intro to Database Schema 

Learn how to set up your database using Prisma, including initializing the schema and configuring new files.

Learn how to create a SQLite database using Prisma, define models with unique fields, and explore data using Prisma Studio. 

Database with Prisma and SQLite

Setting Up the Database with Prisma

Dad Joke Break Database Schema

Database Schema

Intro to Data Relationships

Optimize image storage in a DB: no polymorphism, future-proof for web apps. Learn why it's best for new projects.

Master Prisma relationships: one-to-one, one-to-many, foreign keys, cascading, unique constraints. Dive into DB schema design flexibilities & limits.

One-to-One and One-to-Many Relationships in Prisma

Database Design

Dad Joke Break Data Relationships

Data Relationships

Intro to Data Migrations

Master Prisma migration: create tables, modify props, spin up DBs, deploy across environments with confidence.

Prisma migrations: Seamlessly evolve your DB schema, reap benefits of flexibility and easy updates.

Database Migrations with Prisma

Creating Migration Files for Database Management with Prisma

Dad Joke Break Data Migrations

Data Migrations

Intro to Seeding Data

Configuring Prisma for seamless data seeding using seed scripts in your application.

Creating and Managing Data with Prisma Seed Scripts

Configuring Prisma for Seed Script Execution

Leverage Prisma nested mutations for efficient data handling, query optimization, and seamless retrieval. 

Efficiently manage relational records with nested queries. Explore benefits and considerations of nesting in DB ops.

Nested Queries in Database Operations

Optimizing Queries with Nested Mutations in Prisma

Dad Joke Break Seeding Data

Seeding Data

Intro to Generating Seed Data

Automatically generate realistic fake data for efficient testing with powerful tools.

Use Faker.js for realistic random user and note data, automating database population matching your schema. 

Generating Random User Data with Faker.js for Database Seeding

Generating Fake Data for Efficient Testing

Effortlessly generate dynamic web app data: user profiles, images, notes, with time-saving techniques.  

Create dynamic seed data with Faker and Prisma: random users, notes, images. Boost data generation efficiency and flexibility.

Generating Dynamic Seed Data 

Dynamically Generating Data

Enforce Unique: Seed user data with unique values, reduce collisions, and optimize queries.

Create seed data with unique valid usernames, enforce integrity, and safeguard against failures.

Generating Unique and Valid Usernames in Seed Data

Creating Unique User Data with Enforce Unique Library

Dad Joke Break Generating Seed Data

Generating Seed Data

Intro to Querying Data

Learn how to migrate from an in-memory database to a real database using Prisma and SQLite, enabling the loading of actual data in your application.

Optimize Prisma Client: Lazy connections, custom logging, and speed up app with query performance.

Optimizing Prisma Client for Efficient Database Operations

Connecting to a Real Database with Prisma and SQLite

Transition from in-memory to real database with Prisma, efficient SELECT queries for user data, type safety advantages.

Shift to Prisma SQLite DB, type-safe queries for specific fields, end-to-end type safety in web apps. 

Using Prisma to Retrieve User Data from a SQLite Database

Transitioning to Real Database with Prisma API

Learn how to optimize note loading by combining multiple queries into a single query and migrating to Prisma for real database integration.

Optimize data retrieval with Prisma, subselects for efficiency, TypeScript error-catching, and migration guidance. 

Efficient Data Retrieval with Prisma and Subselects

Database Queries and Migrating to Prisma 

Dad Joke Break Querying Data

Querying Data

Intro to Updating Data

Delete data from the actual database using Prisma. This exercise introduces a straightforward mutation before diving into more complex concepts.

Discover how easy it is to delete data using Prisma's syntax and APIs. 

Deleting Data with Prisma

Mutating Data with Prisma

Mutations for updating images and notes on a page, including cache control considerations and utilizing helpful utilities for easier data manipulation.

Learn how to update and delete data in a form using Prisma, while handling image updates, removing deleted images, and creating new images. 

Efficiently Updating and Deleting Data in a Form with Prisma

Updating Page Mutations for Images and Notes with Efficient Cache Control

Learn how to use transactions to ensure that data operations within your application either succeed completely or fail entirely. 

Learn how to use prisma.transaction to ensure a group of database operations either all succeed or all fail together

Implementing Transactions with Prisma for Atomic Database Operations

Implementing Transactions for Reliable Data Operations

Learn how to use nested queries in Prisma to combine multiple database operations into a single optimized query, reducing the number of calls made to the db. 

Learn how to optimize database updates using Prisma by combining multiple related queries into a single transaction, resulting in cleaner, more efficient code. 

Efficient Database Updates with Prisma's Nested Queries

Optimizing Database Calls with Nested Queries in Prisma

Dad Joke Break Updating Data

Updating Data

Intro to SQL

Master advanced user search with Prisma: Write raw SQL queries, iterate from basic search to SQLite database display.

Search users with Prisma raw queries by criteria, handle TypeScript hurdles, prep for adding images.

User Search with Prisma and SQL

SQL Queries for User Search in Prisma

Tackle TypeScript errors in Prisma raw queries, ensure type safety with Zod runtime checks. Weigh Prisma's trade-offs.

Embrace runtime type checks in Prisma for robust DB interaction, handle schema changes and parsing errors.

Runtime Type Checking and Parsing in Prisma with Raw Queries

Handling TypeScript Errors and Runtime Type Checking with Prisma and Zod

Efficiently combine data with SQL joins: inner, left, right, full. Get user profile photos without performance issues.

Master left joins in Prisma/SQLite, resolve conflicts, enrich schema, and improve UI with extra properties.

Left Joins with Prisma and SQLite

Working with Joins in SQL

Sort users by most recent note updates using Prisma raw SQL queries. Follow step-by-step instructions.

AI assistants like GitHub Copilot for SQL queries: benefits, best practices, code review, productivity, accuracy. 

Leveraging AI Assistance for Writing SQL Queries

Sorting Users by Recent Entry with Raw SQL

Dad Joke Break SQL

Intro to Query Optimization

Boost Prisma query performance: Add non-unique foreign key indexes, verify with 'explain query' for speed!

Optimize DB queries with user-specific note indexes, boosting performance and reducing scan times.

Optimizing Database Queries with Indexes

Optimizing Query Performance with Indexes in Prisma

Enhance slow user search with single index in SQLite, sidestep caching complexities, grasp query plans, and boost DB performance.

Learn how to analyze query plans and optimize query performance by adding indexes to improve speed and avoid unnecessary scans and temporary data structures.

Data Modeling Deep Dive

Data Modeling Deep Dive

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One-to-Many Relationships

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