DYNDB009: Unsupported property type

Field	Value
Code	DYNDB009
Severity	Error

Message

Property '{0}' has type '{1}' which is not supported for DynamoDB mapping

Description

Only certain .NET types can be automatically mapped to DynamoDB attribute values. The source generator supports primitive types, DateTime, collections (List, HashSet, Dictionary), and types marked with [DynamoDbEntity]. Types that cannot be serialized to a DynamoDB AttributeValue are rejected.

Example

The following code triggers this diagnostic:

[DynamoDbTable("Events")]
public partial class Event
{
    [PartitionKey]
    [DynamoDbAttribute("pk")]
    public string Pk { get; set; } = string.Empty;

    [DynamoDbAttribute("callback")]
    public Action<string> Callback { get; set; } = _ => { };
}

Fix

The corrected version:

[DynamoDbTable("Events")]
public partial class Event
{
    [PartitionKey]
    [DynamoDbAttribute("pk")]
    public string Pk { get; set; } = string.Empty;

    [DynamoDbAttribute("callbackUrl")]
    public string CallbackUrl { get; set; } = string.Empty;
}