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query4k

Most recent version: 1.0.0

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Interact with your database in a safe and efficient manner, without the burden of ORMs.

Query4k was developed with the aim of offering a straightforward and simple solution for accessing your database. It eliminates the need for intricate setups or cumbersome ORMs, ensuring a user-friendly experience without the burden of handling low-level intricacies.

Adding query4k to your project is as simple as decorating your data classes with @Serializable!

Tested with H2 and PostgreSQL, should work with any SQL database.

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Getting started

More details at https://github.com/o-korpi/query4k/wiki/Documentation.

Installation

Query4k requires Kotlinx Serialization to run. You will also need the Arrow core library to handle results from function calls.

plugins {
    kotlin("plugin.serialization") version "1.9.0"
}

dependencies {
    implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.5.1")
    implementation("io.arrow-kt:arrow-core:1.2.0")
}

If you want to make use of UUIDs you also need the following dependency: implementation("app.softwork:kotlinx-uuid-core:0.0.21")

For now, UUIDs cannot be inserted in an injection-safe manner, and direct insertions together with .toSQLParseable() are necessary.

Query4k is not yet on the maven repository. To use you must download and compile the project, or install the jar provided in releases.

Usage

First create an instance of Query4k, using your preferred method.

val q4k = Query4k.create("postgresql://postgres:postgres@localhost:5432/postgres")

With an instance of Query4k, we can now interact with our database.

q4k.execute(
    "INSERT INTO users (email) VALUES (:email)", 
    mapOf("email" to "[email protected]")
)

Notice how SQL injection is dealt with.

To query our database, we first need to create our model. Models in query4k are just simple serializable dataclasses.

@Serializable
data class User(
    val id: Long,
    val email: String
)

With our model defined, we can use the query method:

q4k.query<User>("SELECT * FROM users")

Like the execute method, we can also provide injection-safe parameters here.

To use transactions, we make use of the self-closing transaction block.

q4k.transaction {
    execute("INSERT INTO users (email) VALUES (:email)", mapOf("email" to "example"))
    println(query<User>("SELECT * FROM users"))
}