https://github.com/hfhbd/postgres-native-sqldelight

A Kotlin native Postgres driver for SqlDelight.
https://github.com/hfhbd/postgres-native-sqldelight

kotlin-native postgresql sqldelight

Last synced: about 2 months ago
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A Kotlin native Postgres driver for SqlDelight.

• Host: GitHub
• URL: https://github.com/hfhbd/postgres-native-sqldelight
• Owner: hfhbd
• License: apache-2.0
• Created: 2022-05-13T17:17:04.000Z (over 2 years ago)
• Default Branch: main
• Last Pushed: 2024-10-16T06:34:32.000Z (3 months ago)
• Last Synced: 2024-10-17T23:08:17.867Z (3 months ago)
• Topics: kotlin-native, postgresql, sqldelight
• Language: Kotlin
• Homepage: https://postgresnative.softwork.app/
• Size: 671 KB
• Stars: 36
• Watchers: 2
• Forks: 3
• Open Issues: 6
• Metadata Files:
  • Readme: README.md
  • Funding: .github/FUNDING.yml
  • License: LICENSE

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README

        
# PostgreSQL native SQLDelight driver

A native Postgres driver using libpq.

You can use the driver with [SQLDelight](https://github.com/cashapp/sqldelight), but this is not required.

- [Source code](https://github.com/hfhbd/postgres-native-sqldelight)

> Keep in mind, until now, this is only a single-threaded wrapper over libpq using 1 connection only. There is no

> connection pool nor multithread support (like JDBC or R2DBC).

## Install

You need `libpq` installed and available in your `$PATH`.

This package is uploaded to MavenCentral and supports macOS and linuxX64.

Windows is currently not supported.

````kotlin

repositories {

    mavenCentral()

}

dependencies {

    implementation("app.softwork:postgres-native-sqldelight-driver:LATEST")

}

// optional SQLDelight setup:

sqldelight {

    databases.register("NativePostgres") {

        dialect("app.softwork:postgres-native-sqldelight-dialect:LATEST")

    }

    linkSqlite.set(false)

}

````

## Usage

```kotlin

val driver = PostgresNativeDriver(

    host = "localhost",

    port = 5432,

    user = "postgres",

    database = "postgres",

    password = "password",

    options = null,

    listenerSupport = ListenerSupport.Remote(coroutineScope)

)

```

### Listeners

This driver supports local and remote listeners.

Local listeners only notify this client, ideally for testing or using the database with only one client at a time.

Remote listener support uses `NOTIFY` and `LISTEN`, so you can use this to sync multiple clients or with existing

database

triggers.

SQLDelight uses and expects the table name as payload, but you can provide a mapper function.

### SQLDelight Support

Just create the driver and use your database instances in the usual way.

### Raw usage

Beside SQLDelight you could also use this driver with raw queries.

The identifier is used to reuse prepared statements.

```kotlin

driver.execute(identifier = null, sql = "INSERT INTO foo VALUES (42)", parameters = 0, binders = null)

```

It also supports a real lazy cursor by using a `Flow`. The `fetchSize` parameter defines how many rows are fetched at

once:

```kotlin

val namesFlow: Flow = driver.executeQueryAsFlow(

    identifier = null,

    sql = "SELECT index, name, bytes FROM foo",

    mapper = { cursor ->

        Simple(

            index = cursor.getLong(0)!!.toInt(),

            name = cursor.getString(1),

            byteArray = cursor.getBytes(2)

        )

    },

    parameters = 0,

    fetchSize = 100,

    binders = null

)

```

And for bulk imports, use the `copy` method. You need to enable `COPY` first:

```kotlin

driver.execute(514394779, "COPY foo FROM STDIN (FORMAT CSV)", 0)

val rows = driver.copy("1,2,3\n4,5,6\n")

```

## License

Apache 2

## Contributing

### Devcontainers

Start the devcontainer, that's it.

### Local

#### docker compose

This is the preferred local option. The `app` service contains the JVM as well as libpq.

#### Manual

You need to install `libpq`, eg using Homebrew: https://formulae.brew.sh/formula/libpq#default

For installation using homebrew, the default path is already added.

Otherwise, you have to add the compiler flags to

the [libpq.def](postgres-native-sqldelight-driver/src/nativeInterop/cinterop/libpq.def).

The exact flags depend on your config, for example:

```

For compilers to find libpq you may need to set:

  export LDFLAGS="-L/home/linuxbrew/.linuxbrew/opt/libpq/lib"

  export CPPFLAGS="-I/home/linuxbrew/.linuxbrew/opt/libpq/include"

```

##### Testing

If you installed libpq with homebrew, it will install the platform-specific artifact.

To test other platforms, eg. linux x64 on macOS, you need to install the platform-specific libpq of linux x64 too.

To start the postgres instance, you can use docker:

```sh

docker run -e POSTGRES_PASSWORD=password -p 5432:5432 postgres

```