DuckDB ODBC Driver Misaligns Data Types with OLEDB

[gustavoleo]

For example, DECIMAL is mapped to the OLEDB type 21

OLEDB type 21 is UnsignedBigInt

OLEDB types are here: https://learn.microsoft.com/en-us/dotnet/api/system.data.oledb.oledbtype?view=net-9.0-pp

To reproduce use the https://blobs.duckdb.org/data/tpch-sf1.db

[staticlibs]

@gustavoleo

Hi, thanks for the report! Can you share more details on your setup, how you access the DuckDB ODBC. Are you using MSDASQL provider from .NET? Also there is a pending PR #81 that changes data type mapping for DECIMALs. Overall the type presented to client app needs to be re-checked (using the same setup as that app is using) and corrected if needed.

[gustavoleo]

We are using on AnalyticsCreator, as ODBC connection. I will check with my co-worker if he could provide more details.
We migth be able to reproduce the issue using Visual Studio and ODBC Connection.

[staticlibs]

@gustavoleo

Thanks for the details! I will investigate this.

[gustavoleo]

Here new infos I dont know if helps you

to connect I use System.Data.Odbc

To obtain metadata information I use OdbcConnection.GetSchema

[staticlibs]

@gustavoleo

I've filed #128 in attempt to fix this. The following types are reported by OdbcConnection now - mapping. System.Decimal is used for unsigned 64-bit integers and 128-bit integers because these types are not supported in .NET CLS.

This mapping is open for additional corrections, please let us know if this change will break something on your app side.