Driver Manager calls SQLGetDiagFieldW with wrong handle type for SQL_DYNAMIC_FUNCTION_CODE and SQL_DYNAMIC_FUNCTION

[sjoshi-simba]

Summary

When retrieving diagnostic fields such as SQL_DYNAMIC_FUNCTION_CODE or SQL_DYNAMIC_FUNCTION, the Driver Manager calls SQLGetDiagFieldW with HandleType=SQL_HANDLE_DBC (connection) even though the Handle provided is that of a statement. According to the ODBC specification, these fields are statement-level diagnostics and should only ever be requested with a statement handle.

Reference in code:
https://github.com/openlink/iODBC/blob/develop/iodbc/herr.c#L1690

Expected Behavior

When requesting the dynamic function code from a statement, the Driver Manager should call into the driver with:

• HandleType = SQL_HANDLE_STMT
• Handle = valid statement handle

Actual Behavior

iODBC calls the driver with:

• HandleType = SQL_HANDLE_DBC
• Handle = actually a statement handle
• DiagIdentifier = SQL_DYNAMIC_FUNCTION_CODE or SQL_DYNAMIC_FUNCTION

This causes drivers to fail to find the appropriate diagnostic manager, as the handle maps to a statement but the type signals it should locate a connection object.

Impact

• Drivers that rely on correct diagnostic retrieval for statement operations are broken, including proper error reporting when using iODBC.

Reproduction Steps

1. Execute a statement using any ODBC driver with iODBC as the Driver Manager
2. Request diagnostic field SQL_DYNAMIC_FUNCTION_CODE or SQL_DYNAMIC_FUNCTION via SQLGetDiagField
3. Observe that the driver's implementation receives HandleType=SQL_HANDLE_DBC, even though the handle is not a connection

ODBC Specification Reference

See ODBC documentation for SQLGetDiagField, which prescribes which handle types are allowed/valid for a given DiagIdentifier:

SQL_DYNAMIC_FUNCTION_CODE (and SQL_DYNAMIC_FUNCTION) are only valid for statement handles.

https://learn.microsoft.com/en-us/sql/odbc/reference/syntax/sqlgetdiagfield-function?view=sql-server-ver16

Recommendation

Please correct the iODBC Driver Manager logic to ensure that statement-specific diagnostic fields are only ever requested on statement handles using HandleType=SQL_HANDLE_STMT.

[HughWilliams]

We are looking into this ...