Snowflake Conversion

Discord IDs are 64-bit ulong snowflakes. Most relational providers — including PostgreSQL/Npgsql and SQL Server — lack native unsigned 64-bit support and store integers as signed long. Persistord bridges the gap in one place so you never have to annotate individual properties.

How it works

Persistord.Core ships two EF Core value converters:

• UlongToLongConverter — converts ulong ↔ long using unchecked((long)value) and unchecked((ulong)value).
• NullableUlongToLongConverter — the same round-trip for ulong? ↔ long?.

The unchecked cast is bit-faithful: the 64 bits are reinterpreted without range checking, so every value — including snowflakes with the high bit set — survives storage exactly.

Global registration

DiscordDbContext registers both converters in ConfigureConventions, so the conversion applies to every ulong and ulong? property in your derived context automatically:

protected override void ConfigureConventions(ModelConfigurationBuilder builder)
{
    builder.Properties<ulong>().HaveConversion<UlongToLongConverter>();
    builder.Properties<ulong?>().HaveConversion<NullableUlongToLongConverter>();
}

You never annotate individual IDs. Inherit DiscordDbContext and all snowflake properties in your model — including those in module entities — are handled.

Storage note

Snowflakes are stored as long in the database column. Discord snowflakes remain below long.MaxValue until roughly the year 2084, so signed storage is safe in practice. The converter is nevertheless bit-faithful and would round-trip correctly even past that point.

See also

• Core Graph — the base DiscordDbContext and the skeleton entities whose ulong IDs this conversion covers.