ldbc Tutorial

ldbc is a type-safe MySQL database client written in Scala 3. It allows you to write SQL safely and concisely while leveraging Scala's powerful type system to reduce database operation errors.

Key Features of ldbc

Type Safety: Detects SQL query issues at compile time
Concise Syntax: Intuitive query writing using SQL string interpolation
Cats Effect Integration: Supports pure functional programming
Schema Auto-generation: Generate Scala code from SQL
Query Builder: Build type-safe queries without writing SQL directly

Quick Start

Let's first take a look at the basic usage of ldbc. Here's a simple example of retrieving user information from the database and adding a new user:

import cats.effect.*
import cats.syntax.all.*
import ldbc.connector.*
import ldbc.dsl.*

// Database connection configuration
val provider =
  ConnectionProvider
    .default[IO]("127.0.0.1", 3306, "ldbc", "password", "ldbc")
    .setSSL(SSL.Trusted)

// Executing queries
val program = for
  // Retrieving user list
  users <- sql"SELECT id, name FROM user".query[(Int, String)].to[List]
  
  // Adding a new user
  _ <- sql"INSERT INTO user (name, email) VALUES ('Taro Yamada', 'yamada@example.com')".update
  
  // Checking user count after update
  count <- sql"SELECT COUNT(*) FROM user".query[Int].unsafe
yield (users, count)

// Executing the program
provider.use { conn =>
  program.transaction(conn)
}

How to Proceed with this Tutorial

This tutorial series is structured to help you learn ldbc step by step. We recommend proceeding in the following order:

1. Setup

First, let's prepare the environment for using ldbc.

Setup - Preparing development environment and database
Connection - How to connect to a database

2. Basic Operations

Next, let's learn frequently used features for everyday tasks.

Simple Program - Execute your first simple queries
Parameters - Queries with parameters
Selecting Data - Retrieving data with SELECT statements
Updating Data - INSERT/UPDATE/DELETE operations
Database Operations - Transaction management

3. Advanced Operations

After understanding the basics, let's move on to more advanced features.

Error Handling - Exception handling
Logging - Query logging
Custom Data Types - Support for custom data types
Query Builder - Type-safe query construction
Schema - Table definitions
Schema Code Generation - Code generation from SQL

Why Choose ldbc?

Low Learning Curve: String interpolation that leverages your existing SQL knowledge
Safety: Early bug detection through compile-time type checking
Productivity: Reduction of boilerplate code and automatic code generation
Performance: Optimized MySQL connection management
Benefits of Functional Programming: Composability through Cats Effect integration

Now, let's start with Setup!