To reproduce

Consider the following C# program:

using Npgsql;

await using var dataSource = new NpgsqlDataSourceBuilder(
    "Host=127.0.0.1;Port=8812;Username=admin;Password=quest;Database=qdb;ServerCompatibilityMode=NoTypeLoading;"
).Build();

await using var connection = await dataSource.OpenConnectionAsync();
await using var batch = new NpgsqlBatch(connection);

var cmd1 = new NpgsqlBatchCommand("SELECT @time;");
cmd1.Parameters.AddWithValue("time", DateTime.UtcNow);
batch.BatchCommands.Add(cmd1);

var cmd2 = new NpgsqlBatchCommand("SELECT @time;");
cmd2.Parameters.AddWithValue("time", DateTime.UtcNow);
batch.BatchCommands.Add(cmd2);

await batch.PrepareAsync(); // It works if we do not prepare the batch

await using var reader = await batch.ExecuteReaderAsync();

while (await reader.ReadAsync())
{
    Console.WriteLine(reader.GetDateTime(0));
}
await reader.NextResultAsync();
while (await reader.ReadAsync())
{
    Console.WriteLine(reader.GetDateTime(0));
}

I get this exception when processing the second result:

System.InvalidCastException
HResult=0x80004002
Message=Out of range of DateTime (year must be between 1 and 9999).
Source=Npgsql
StackTrace:
at Npgsql.Internal.Converters.PgTimestamp.Decode(Int64 value, DateTimeKind kind, Boolean dateTimeInfinityConversions)
at Npgsql.Internal.Converters.DateTimeConverter.ReadCore(PgReader reader)
at Npgsql.Internal.PgBufferedConverter`1.Read(PgReader reader)
at Npgsql.NpgsqlDataReader.GetFieldValueCore[T](Int32 ordinal)
at Npgsql.NpgsqlDataReader.GetDateTime(Int32 ordinal)
at Program.<

$>d__0.MoveNext() in C:\Source\ConsoleApp1\ConsoleApp1\Program.cs:line 29
at Program.<$>d__0.MoveNext() in C:\Source\ConsoleApp1\ConsoleApp1\Program.cs:line 27
at Program.<$>d__0.MoveNext() in C:\Source\ConsoleApp1\ConsoleApp1\Program.cs:line 27
at Program.<$>d__0.MoveNext() in C:\Source\ConsoleApp1\ConsoleApp1\Program.cs:line 27
at Program.<$>d__0.MoveNext() in C:\Source\ConsoleApp1\ConsoleApp1\Program.cs:line 27
This exception was originally thrown at this call stack:
[External Code]
Inner Exception 1:
ArgumentOutOfRangeException: Ticks must be between DateTime.MinValue.Ticks and DateTime.MaxValue.Ticks. (Parameter 'ticks')

Maybe related issue #6123.

QuestDB version:

9.3.1

OS, in case of Docker specify Docker and the Host OS:

Windows

File System, in case of Docker specify Host File System:

ntfs

Full Name:

Rasmus Melchior Jacobsen

Affiliation:

Utiliread ApS

Have you followed Linux, MacOs kernel configuration steps to increase Maximum open files and Maximum virtual memory areas limit?

• Yes, I have

Additional context

No response