https://github.com/komapper/komapper
Kotlin ORM for JDBC and R2DBC
https://github.com/komapper/komapper
jdbc kotlin ksp orm r2dbc server-side sql
Last synced: 3 months ago
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Kotlin ORM for JDBC and R2DBC
- Host: GitHub
- URL: https://github.com/komapper/komapper
- Owner: komapper
- License: apache-2.0
- Created: 2021-03-21T05:35:15.000Z (almost 5 years ago)
- Default Branch: main
- Last Pushed: 2025-02-11T12:00:32.000Z (11 months ago)
- Last Synced: 2025-02-11T12:05:42.548Z (11 months ago)
- Topics: jdbc, kotlin, ksp, orm, r2dbc, server-side, sql
- Language: Kotlin
- Homepage: https://www.komapper.org
- Size: 6.2 MB
- Stars: 308
- Watchers: 9
- Forks: 16
- Open Issues: 8
-
Metadata Files:
- Readme: README.md
- Funding: .github/FUNDING.yml
- License: LICENSE
- Code of conduct: CODE_OF_CONDUCT.md
Awesome Lists containing this project
- awesome-java - Komapper
README
Komapper: Kotlin ORM for JDBC and R2DBC
========================================
[](https://github.com/komapper/komapper/actions/workflows/build.yml)
[](https://twitter.com/komapper)
[](https://kotlinlang.slack.com/messages/komapper/)
[](https://search.maven.org/artifact/org.komapper/komapper-platform)
[](https://deepwiki.com/komapper/komapper)
Komapper is an ORM library for server-side Kotlin.
For more documentation, go to our site:
- https://www.komapper.org/docs/
## Features
### Highlighted
- Support for both JDBC and R2DBC
- Code generation at compile-time using [Kotlin Symbol Processing API](https://github.com/google/ksp)
- Immutable and composable queries
- Support for Kotlin value classes
- Easy Spring Boot integration
### Experimental
- Quarkus integration
- Transaction management using context receivers
## Prerequisite
- Kotlin 1.9.24 or later
- JRE 11 or later
- Gradle 6.8.3 or later
## Supported Databases
Komapper is tested with the following databases:
| Database | version | JDBC support | R2DBC support |
|--------------------|---------|:------------:|:-------------:|
| H2 Database | 2.3.232 | v | v |
| MariaDB | 10.6.3 | v | v |
| MySQL v5.x | 5.7.44 | v | v |
| MySQL v8.x | 8.0.25 | v | v |
| Oracle Database XE | 18.4.0 | v | v |
| PostgreSQL | 12.9 | v | v |
| SQL Server | 2019 | v | (unstable) |
Supported connectivity types:
- JDBC 4.3
- R2DBC 1.0.0
## Installation
Add the following code to the Gradle build script (gradle.build.kts).
```kotlin
plugins {
kotlin("jvm") version "2.2.20"
id("com.google.devtools.ksp") version "2.2.20-2.0.3"
}
val komapperVersion = "5.6.0"
dependencies {
platform("org.komapper:komapper-platform:$komapperVersion").let {
implementation(it)
ksp(it)
}
implementation("org.komapper:komapper-starter-jdbc")
implementation("org.komapper:komapper-dialect-h2-jdbc")
ksp("org.komapper:komapper-processor")
}
```
See also Quickstart for more details:
- https://www.komapper.org/docs/quickstart/
## Sample code
To get complete code, go to our [example repository](https://github.com/komapper/komapper-examples).
### Entity class definition
```kotlin
@KomapperEntity
data class Address(
@KomapperId
@KomapperAutoIncrement
@KomapperColumn(name = "ADDRESS_ID")
val id: Int = 0,
val street: String,
@KomapperVersion
val version: Int = 0,
@KomapperCreatedAt
val createdAt: LocalDateTime? = null,
@KomapperUpdatedAt
val updatedAt: LocalDateTime? = null,
)
```
### Connecting with JDBC
```kotlin
fun main() {
// create a Database instance
val db = JdbcDatabase("jdbc:h2:mem:example;DB_CLOSE_DELAY=-1")
// get a metamodel
val a = Meta.address
// execute simple operations in a transaction
db.withTransaction {
// create a schema
db.runQuery {
QueryDsl.create(a)
}
// INSERT
val newAddress = db.runQuery {
QueryDsl.insert(a).single(Address(street = "street A"))
}
// SELECT
val address = db.runQuery {
QueryDsl.from(a).where { a.id eq newAddress.id }.first()
}
}
}
```
### Connecting with R2DBC
```kotlin
suspend fun main() {
// create a Database instance
val db = R2dbcDatabase("r2dbc:h2:mem:///example;DB_CLOSE_DELAY=-1")
// get a metamodel
val a = Meta.address
// execute simple operations in a transaction
db.withTransaction {
// create a schema
db.runQuery {
QueryDsl.create(a)
}
// INSERT
val newAddress = db.runQuery {
QueryDsl.insert(a).single(Address(street = "street A"))
}
// SELECT
val address = db.runQuery {
QueryDsl.from(a).where { a.id eq newAddress.id }.first()
}
}
}
```
## Design Policy
See [DESIGN_DOC](DESIGN_DOC.md) for the design policy of this project.
## Compatibility Matrix
| Kotlin and KSP version | Komapper version | KSP2 support? | JRE min version | Gradle min version |
|:-----------------------|:-----------------|---------------|:----------------|--------------------|
| 1.9.24-1.0.20 | 1.18.1 - 2.x | No | 11 | 6.8.3 |
| 2.0.21-1.0.28 | 2.x - 5.x | Yes | 11 | 7.6.4 |
| 2.1.21-2.0.2 | 5.x | Yes | 11 | 7.6.4 |
| 2.2.20-2.0.3 | 5.x | Yes | 11 | 7.6.4 |
Compatibility testing is performed in the [komapper/compatibility-test](https://github.com/komapper/compatibility-test/) repository.
## Backers
If you use Komapper in your project or enterprise and would like to support ongoing development,
please consider becoming a backer. [[Become a backer](https://opencollective.com/komapper#category-CONTRIBUTE)]
Our top backers are shown below!
