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FDDB101: Explicit discriminator pattern conflicts with key format

FieldValue
CodeFDDB101
SeverityError

Message​

Entity '{0}' specifies DiscriminatorPattern on attribute '{1}' as '{2}' but the key format derives pattern '{3}'

Description​

When an entity has both an explicit DiscriminatorPattern and a key format that automatically derives a discriminator pattern, these two patterns must be consistent. The source generator derives a pattern from the key's prefix and format structure; if the explicitly specified pattern contradicts this derivation, it creates an irreconcilable conflict.

Remove the explicit DiscriminatorPattern and let the source generator derive it automatically from the key format, or adjust the explicit pattern to match what the key format would derive.

Example​

The following code triggers this diagnostic:

[DynamoDbTable("shared-table",
    DiscriminatorPattern = "CUSTOMER#*")]
public partial class Order
{
    [PartitionKey(Prefix = "ORDER")]
    [DynamoDbAttribute("pk")]
    public string Pk { get; set; } = string.Empty;

    [SortKey]
    [DynamoDbAttribute("sk")]
    public string Sk { get; set; } = string.Empty;
}

Fix​

The corrected version:

[DynamoDbTable("shared-table")]
public partial class Order
{
    [PartitionKey(Prefix = "ORDER")]
    [DynamoDbAttribute("pk")]
    public string Pk { get; set; } = string.Empty;

    [SortKey]
    [DynamoDbAttribute("sk")]
    public string Sk { get; set; } = string.Empty;
}
// Pattern "ORDER#*" is auto-derived from Prefix = "ORDER"