Npgmq

A .NET client for Postgres Message Queue (PGMQ).

Compatibility

• pgmq >= 0.31.0

Installation

To install the package via Nuget, run the following command:

dotnet add package Npgmq

Usage

Here is an example that uses Npgmq to create a queue and then send/read/archive a message:

using Npgmq;

var npgmq = new NpgmqClient("<YOUR CONNECTION STRING HERE>");

await npgmq.InitAsync();

await npgmq.CreateQueueAsync("my_queue");

var msgId = await npgmq.SendAsync("my_queue", new MyMessageType
{
    Foo = "Test",
    Bar = 123
});
Console.WriteLine($"Sent message with id {msgId}");

var msg = await npgmq.ReadAsync<MyMessageType>("my_queue");
if (msg != null)
{
    Console.WriteLine($"Read message with id {msg.MsgId}: Foo = {msg.Message?.Foo}, Bar = {msg.Message?.Bar}");
    await npgmq.ArchiveAsync("my_queue", msg.MsgId);
}

This example assumes you have defined a class called MyMessageType with the structure something like:

public class MyMessageType
{
    public string Foo { get; set; } = null!;
    public int Bar { get; set; }
}

You can send and read messages as JSON strings, like this:

var msgId = await npgmq.SendAsync("my_queue", "{\"foo\":\"Test\",\"bar\":123}");
Console.WriteLine($"Sent message with id {msgId}");

var msg = await npgmq.ReadAsync<string>("my_queue");
if (msg != null)
{
    Console.WriteLine($"Read message with id {msg.MsgId}: {msg.Message}");
    await npgmq.ArchiveAsync("my_queue", msg.MsgId);
}

You can pass your own NpgsqlConnection to the NpgmqClient constructor, like this:

using var myConnection = new NpgsqlConnection("<YOUR CONNECTION STRING HERE>");
var npgmq = new NpgmqClient(myConnection);

Database Connection

Npgmq uses Npgsql internally to connect to the database.

Using a Connection String

If you pass an Npgsql connection string to the NpgmqClient constructor, it will use this connection string to create an NpgsqlConnection object internally, and the connection lifetime will be managed by NpgmqClient.

Using a Connection Object

If you pass an NpgsqlConnection object to the NpgmqClient constructor, it will use this connection instead of creating its own.