Handlers · 1 min read

DuckDbStreamToByteArrayPropertyHandler

A property handler that maps a DuckDB BLOB column onto a byte array property.

A property handler that maps a DuckDB BLOB column onto a byte[] property. DuckDB.NET returns an unmanaged Stream when reading a BLOB value, which has no built-in coercion to byte[]. Writing is unaffected — a byte[] parameter value is already accepted natively by DuckDB.NET, so only the read direction needs this handler.

DuckDbBootstrap registers this handler as the default, type-level handler for every byte[] property, so it applies automatically without any attribute or manual mapping. Pass addDefaultHandlers: false to UseDuckDb() to opt out and register your own byte[] handler instead.

Overview

Name	Description
Class	`DuckDbStreamToByteArrayPropertyHandler`
Namespace	`RepoDb.PropertyHandlers.DuckDb`
Package	RepoDb.DuckDb
Implements	IPropertyHandler`<object, byte[]>`
Column type	The DuckDB `BLOB` type
Property type	`byte[]`

Conversions

Method	Direction	Description
Get	Database to property	Returns the value as-is when it is already a `byte[]`; copies the `Stream` returned by the driver into a `byte[]` otherwise. Returns an empty array when the value is neither.
Set	Property to database	Passes the `byte[]` through unchanged, to be written into a `BLOB` column.

Usability

public class Document
{
    public int Id { get; set; }
    public byte[] Content { get; set; }
}

using (var connection = new DuckDBConnection(ConnectionString))
{
    connection.Insert(new Document { Id = 1, Content = File.ReadAllBytes("file.pdf") });
    var document = connection.Query<Document>(e => e.Id == 1).First();
}

To override the default registration, either disable it via addDefaultHandlers: false before mapping your own, or force-overwrite it directly:

PropertyHandlerMapper.Add<byte[], MyCustomStreamToByteArrayPropertyHandler>(new MyCustomStreamToByteArrayPropertyHandler(), true);