Handlers · 2 min read

SqlServerVectorToFloatArrayPropertyHandler

A property handler that maps the SQL Server vector type into a float array property.

A property handler that maps the SQL Server vector type into a float array property.

Reading requires a version of Microsoft.Data.SqlClient that returns the vector type as a SqlVector<float>. A value that is returned in any other form is read as null.

Overview

Name	Description
Class	`SqlServerVectorToFloatArrayPropertyHandler`
Namespace	`RepoDb.PropertyHandlers.SqlServer`
Package	RepoDb.SqlServer
Implements	IPropertyHandler`<object, float[]>`
Column type	The SQL Server `vector` type
Property type	`float[]`

Conversions

Method	Direction	Description
Get	Database to property	Converts the `SqlVector<float>` returned by the driver into a `float[]`. Any other value, including a null vector, is returned as `null`.
Set	Property to database	Converts the `float[]` into its JSON array text (for example `[1.5,2.5,3.5]`, using the invariant culture), which SQL Server converts implicitly when written into a `vector` column. A `null` array is written as `null`.

Usability

Bind the handler to the property that maps to a vector(n) column.

Attribute

public class Embedding
{
    public int Id { get; set; }

    [Map("vector"), PropertyHandler(typeof(SqlServerVectorToFloatArrayPropertyHandler))]
    public float[] Vector { get; set; }
}

Once bound, the library invokes the handler automatically when the property is read or written.

using (var connection = new SqlConnection(connectionString))
{
    connection.Insert(new Embedding { Id = 1, Vector = new float[] { 1.5f, 2.5f, 3.5f } });
    var embedding = connection.Query<Embedding>(e => e.Id == 1).First();
    // embedding.Vector is a float[] with 3 elements
}

Fluent Mapping

To configure via FluentMapper:

FluentMapper
    .Entity<Embedding>()
    .PropertyHandler<SqlServerVectorToFloatArrayPropertyHandler>(e => e.Vector);

Property Level Mapping

To configure via PropertyHandlerMapper:

PropertyHandlerMapper.Add<Embedding, SqlServerVectorToFloatArrayPropertyHandler>(e => e.Vector, new SqlServerVectorToFloatArrayPropertyHandler(), true);

Type Level Mapping

To apply the handler to every property of the type float[]:

PropertyHandlerMapper.Add<float[], SqlServerVectorToFloatArrayPropertyHandler>(new SqlServerVectorToFloatArrayPropertyHandler(), true);

A type level mapping is process-wide: it is applied to every float[] property of every entity and connection, not only to the intended column. Prefer the attribute, fluent or property level mapping unless every float[] property maps to a vector column.