npgsql 6 breaks after DateTime migration: "year must be between 1 and 9999"

After following the date migration guide to change types from “without time zone” to “with time zone”, I’m still having multiple errors. One of them occurs when reading rows from three of our tables:

Out of the range of DateTime (year must be between 1 and 9999)
   at Npgsql.Internal.TypeHandlers.DateTimeHandlers.DateTimeUtils.ReadDateTime(NpgsqlReadBuffer buf, DateTimeKind kind)
   at Npgsql.Internal.TypeHandlers.DateTimeHandlers.TimestampTzHandler.Read(NpgsqlReadBuffer buf, Int32 len, FieldDescription fieldDescription)
   at Npgsql.Internal.TypeHandling.NpgsqlTypeHandler.Read[TAny](NpgsqlReadBuffer buf, Int32 len, FieldDescription fieldDescription)
   at Npgsql.NpgsqlDataReader.GetFieldValue[T](Int32 ordinal)
   at Npgsql.NpgsqlDataReader.GetDateTime(Int32 ordinal)
   at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.Enumerator.MoveNext()
   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
   at BarreleyeWebTest.BarreleyeIntegrationTestBase.<PrepareTestDatabase>b__17_0(BarreleyeDbContext context) in C:\Dev\BarreleyeServer\BarreleyeWebTest\BarreleyeIntegrationTestBase.cs:line 69

Inner exception:

Ticks must be between DateTime.MinValue.Ticks and DateTime.MaxValue.Ticks. (Parameter 'ticks')
   at System.DateTime.ThrowTicksOutOfRange()
   at System.DateTime..ctor(Int64 ticks, DateTimeKind kind)
   at Npgsql.Internal.TypeHandlers.DateTimeHandlers.DateTimeUtils.DecodeTimestamp(Int64 value, DateTimeKind kind)
   at Npgsql.Internal.TypeHandlers.DateTimeHandlers.DateTimeUtils.ReadDateTime(NpgsqlReadBuffer buf, DateTimeKind kind)

My database contains some dates that I think were set to 0001/01/01 00:00:00, but which BeeKeeper (incorrectly) reports as 0001/12/31… and this breaks npgsql v6. As a workaround I have executed a series of queries like this to fix the problem:

UPDATE table_name
SET last_updated = date '0001-01-02'
WHERE last_updated < date '0001-01-02'

I think the problem can be fixed by changing this function in Npgsql\Internal\TypeHandlers\DateTimeHandlers\DateTimeUtils.cs:

    internal static DateTime DecodeTimestamp(long value, DateTimeKind kind)
        => new(value * 10 + PostgresTimestampOffsetTicks, kind);

do instead:

    internal static DateTime DecodeTimestamp(long value, DateTimeKind kind)
        => new(Math.Max(0, value * 10 + PostgresTimestampOffsetTicks), kind);

or maybe even:

    internal static DateTime DecodeTimestamp(long value, DateTimeKind kind)
        => new(Math.Max(0, Math.Min(DateTime.MaxValue.Ticks, value * 10 + PostgresTimestampOffsetTicks)), kind);

The other error I’m getting occurs when I create a fresh database by calling Migrate().

[roji]

@TriHyde your case seems to be the same as @qwertie - please see the discussion above. You have negative timestamp data in your database, and that’s simply not representable with .NET DateTime. I recommend fixing up your data; for example, you could convert those values to -infinity with a single UPDATE command; after that, Npgsql will read those values as DateTime.MinValue.

If that isn’t suitable, can you please provide more on context on why, and how exactly you’re using those values?

[TriHyde]

Can I reopen this?

I have old data in my database which causes a crash after upgrading to npgsql 6.

An example of a timestamp in the database (which the pgAdmin can read just fine) is “0001-01-01 00:00:00+01:39:49” (in pgAdmin view). pgAdmin does not crash but npgsql does, since it cannot READ that timestamp without throwing this particular exeption: “year must be between 1 and 9999”, inner: “Ticks must be between DateTime.MinValue.Ticks and DateTime.MaxValue.Ticks. (Parameter ‘ticks’)”.

Thanks!