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

[00:00] So let's make a schema for a individual user here. We're going to call this our user search results schema. And we'll just do an individual search result. So each one of these individual users. We're going to bring in Z from Zod. This is going to be an object, and it's going to have an ID.

[00:19] It's not a number copilot. I don't know why copilot really wants IDs to be numbers, but they're super duper not. And then we've got our username and our name is nullable, because our name could possibly not be defined. That's an optional field.

[00:33] And then we're going to make our user search results schema, which is going to be an array of those things. Okay, great. Then down here, we're going to say these are our raw users. This is the unknown thing that we've got. And the question is, okay, Kent, so we're the ones who are controlling the database.

[00:52] We're the ones who are controlling the query. And so why should we do runtime type checking of something that we have total control over? And the answer is that it's very possible that somebody could change the schema so that name is now first name and last name.

[01:11] So they could change the schema in that way, but there would be no checking here to say whether this query is still accurate, right? So you change the schema, but have no protection on this particular query. And then you would end up with our parsing

[01:31] not working properly, or if we don't parse at all, you wouldn't get a useful error. You'd get like a totally useless error. And so by forcing ourselves to parse our own stuff, we're at least giving ourselves a nicer error for when those sorts of things do happen. And hopefully if you have tests,

[01:51] you'll catch that before you actually deploy to production. So parsing will help with that as well. So let's go get our result from our user search results schema, safe parse on the raw users. And then we can say, if result.success, if it's not successful,

[02:09] then we're going to want to return an error. So we'll say, yep, status is error. The error is the result error message. And we'll set that as const. And then also let's give it a status of 400. So browsers behave properly

[02:27] as far as whatever it is that they do on these different pages. Browsers do all sorts of things based on this status code. So always a good idea to keep the proper status code. And then if there's not an error, then we can return a status of idle and the users is now going to be result.data.

[02:44] And just like that, we've got those type issues are gone. We have a new one because of this image. We actually don't have that image there yet. So we're going to just ignore this for now. We'll get to it very soon. And yeah, we're pretty well taken care of.

[03:03] We got a couple of other things that we want to do here, but let's just double check. I can search for Co and there's Cody. So we're in a good place there and everything is nice and type safe. If I miss the username, then we're going to get our error and we need to display that error message. So I'm going to leave that error state right there

[03:23] and let's get our error message displayed. So first off, I'm going to console log the error for my own debugging purposes. We can take a look at our console here and we'll see we've got this error, which should hopefully be helpful in our debugging of whatever the problem was. And then down here,

[03:42] we're going to do something useful for the user. So we'll say, let's bring in this error list and just provide the error. There was an error parsing the results. So the user is not going to be able to do much if this error does happen. So we're not going to give them what the error message was. That's why we log it to the console ourselves.

[04:01] And there we go. There was an error parsing the results. And then you could say like, please report this or whatever, like here's the report email or whatever. But yeah, so now if I restore this to its previous glory, then our users load properly. So we get everything, it's nice and type safe,

[04:18] result.data. and now it's an array at zero. And then, well, yeah, let's come down here. We'll see what that type safe stuff looks like. So we've got the ID and the name and the username. So we are all set there.

[04:38] Again, not my favorite part of Prisma, to be perfectly frank, but I am willing to deal with this because it's such a rare thing that you have to do raw queries. And the workaround for dealing with that, it's not even really a workaround. Like this is a legit API. You can actually use it. You can use regular SQL.

[04:57] And so it's not necessarily a workaround, but the way that you make it type safe with this runtime type checking stuff is, in my mind, is perfectly fine. Now, if you really wanted to, you could, like if you were worried about, oh, like we've got 10,000 results coming back from this, I cannot be parsing that

[05:17] because it's gonna be a performance problem. Then you can, in fact, make this so that you only run this in a development environment. And then in production, you can still get the type safety and all of that, but you, in production, won't actually parse the results and it will still work just the same.

[05:36] So if that's a concern for you in parsing those results, then that's certainly something that you could consider. This tiny bit of extra work is worth it for all of the awesome benefits that Prisma gives us, which is why I'm teaching you Prisma. And that's why I think Prisma is epic. And potentially in the future, I don't think that there's any reason

[05:55] Prisma couldn't itself implement the same types of APIs that some of the other ORMs do offer as well. So if any of you are interested in implementing something like that, that would be a pretty awesome feature to work on. So anyway, hopefully that was a fun exercise for you. Let's keep going.

Handling TypeScript Errors and Runtime Type Checking with Prisma and Zod

[00:00] So what are we going to do about these TypeScript errors? The problem is that data.users is not available on here. The reason it's not available is because this is going to be unknown. We don't know what's going to come back from this Prisma query raw.

[00:18] There are query builders that you can use other tools to interact with your database that could definitely perform this type of a query and make it type safe. But there are a lot of trade-offs associated with using those tools, and I just really, really like Prisma's trade-offs.

[00:34] This is one situation where Prisma doesn't really necessarily shine. Eventually, I think it's very possible that they could implement something like that. But yeah, it's not my favorite part about Prisma. But to be frank, we don't really do a lot of raw queries like this when we're using

[00:54] Prisma anyway. And so I'm actually fine with the way that this is currently set up. It's not my favorite, and it would be cool if it were more type safe, but the fact is it's not. And so we're going to make it type safe with some runtime type checking. So that's what you're going to be doing in this exercise.

[01:13] You have Zod to do some runtime type checking for us. And yeah, we'll talk a little bit more about why you might want to do that when I go through the solution. Give that a shot, and we will 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

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

One-to-Many 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

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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Handling TypeScript Errors and Runtime Type Checking with Prisma and Zod

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