ClickHouse/clickhouse-cpp

Can't cast from Nullable(UInt64)

Sembl4 opened this issue · 1 comments

Hello, everyone!
I try to get a value from Nullable(UInt64) column, and I want to get std::optional<uint64_t> as a result, with this code:

block[col]->AsStrict<AsStrict<ColumnNullableT<ColumnUInt64>>()->At(row);

But I have an exception:

terminate called after throwing an instance of 'clickhouse::ValidationError'
what():  Can't cast from Nullable(UInt64)

I can get a value only this way, and this code works good:

if(!block[b_p_b]->AsStrict<ColumnNullable>()->IsNull(row)){
   std::cout << block[b_p_b]->AsStrict<ColumnNullable>()->GetItem(row).get<uint64_t>() << std::endl;
}

But this way is not very good for me, it would be much better if I could get std::optional<uint64_t> as a result of this operation.
Please tell me how can I do this?
Thanks in advance!

Enmk commented

Hi @Sembl4, thank you for a report!

Could you please specify library version and minimal viable example that against which you are able to reproduce the issue?