[IGNITE-21009] .NET: Thin 3.0: Nullable columns are not supported in KeyValueView with primitive mapping

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.0-beta1
• Fix Version/s: 3.0.0-beta2
• Component/s: platforms, thin client
• Labels: .NET ignite-3

Language

C#

• Assignee: Pavel Tupitsyn
• Reporter: Pavel Tupitsyn
• Reviewer: Igor Sapego
• Created: 04/Dec/23 08:39
• Updated: 04/Jan/24 08:15
• Resolved: 04/Jan/24 08:15

Description

The following test fails:

    [Test]
    public async Task TestPutGetNullable()
    {
        await Client.Sql.ExecuteAsync(null, "CREATE TABLE TestPutGetNullable (ID BIGINT PRIMARY KEY, VAL BIGINT)");
        await Client.Sql.ExecuteAsync(null, "INSERT INTO TestPutGetNullable VALUES (1, 1), (2, NULL)");

        var table = await Client.Tables.GetTableAsync("TestPutGetNullable");
        var view = table!.GetKeyValueView<long, long>();

        var res1 = await view.GetAsync(null, 1);
        var res2 = await view.GetAsync(null, 2);
    }

Result:

System.InvalidOperationException : Binary tuple element with index 1 is null.
   at Apache.Ignite.Internal.Proto.BinaryTuple.BinaryTupleReader.ThrowNullElementException[T](Int32 index) in /home/pavel/w/ignite-3/modules/platforms/dotnet/Apache.Ignite/Internal/Proto/BinaryTuple/BinaryTupleReader.cs:line 572
   at Apache.Ignite.Internal.Proto.BinaryTuple.BinaryTupleReader.GetLong(Int32 index) in /home/pavel/w/ignite-3/modules/platforms/dotnet/Apache.Ignite/Internal/Proto/BinaryTuple/BinaryTupleReader.cs:line 155
   at ReadApache.Ignite.Internal.Table.Serialization.KvPair`2[System.Int64,System.Int64](BinaryTupleReader& )
   at Apache.Ignite.Internal.Table.Serialization.ObjectSerializerHandler`1.Read(MsgPackReader& reader, Schema schema, Boolean keyOnly)
   at Apache.Ignite.Internal.Table.Serialization.RecordSerializer`1.ReadValue(PooledBuffer buf, Schema schema)
   at Apache.Ignite.Internal.Table.RecordView`1.GetAsync(ITransaction transaction, T key)
   at Apache.Ignite.Internal.Table.KeyValueView`2.GetAsync(ITransaction transaction, TK key)
   at Apache.Ignite.Tests.Table.KeyValueViewPrimitiveTests.TestPutGetNullable()

ITable.GetKeyValueView does not allow nullable types ("where TV : notnull") - so we don't have a way to work with nullable columns in this case.
See how Java handles this with additional nullable methods: IGNITE-16115

Option<T> can represent 3 states to handle this situation:

• hasValue=true, value != null
• hasValue=true, value = null
• hasValue=false

Issue Links

• is related to: IGNITE-16115 Implement getNullable and getOrDefault operations.
• links to: GitHub Pull Request #3006