kotlin-exposed-patterns

# Kotlin Exposed Patterns Comprehensive patterns for database access with JetBrains Exposed ORM, including DSL queries, DAO, transactions, and production-ready configuration. ## When to Use - Setting up database access with Exposed - Writing SQL queries using Exposed DSL or DAO - Configuring connection pooling with HikariCP - Creating database migrations with Flyway - Implementing the repository pattern with Exposed - Handling JSON columns and complex queries ## How It Works Exposed provides two query styles: DSL for direct SQL-like expressions and DAO for entity lifecycle management. HikariCP manages a pool of reusable database connections configured via `HikariConfig`. Flyway runs versioned SQL migration scripts at startup to keep the schema in sync. All database operations run inside `newSuspendedTransaction` blocks for coroutine safety and atomicity. The repository pattern wraps Exposed queries behind an interface so business logic stays decoupled from the data layer and tests can use an in-memory H2 database. ## Examples ### DSL Query ```kotlin suspend fun findUserById(id: UUID): UserRow? = newSuspendedTransaction { UsersTable.selectAll() .where { UsersTable.id eq id } .map { it.toUser() } .singleOrNull() } ``` ### DAO Entity Usage ```kotlin suspend fun createUser(request: CreateUserRequest): User = newSuspendedTransaction { UserEntity.new { name = request.name email = reque...