Following error occurs running an Oracle heterogeneous query using CASE function:
"[Microsoft][ODBC Microsoft Access Driver] Unrecognized keyword WHEN"
Toad Base Edition hands over Heterogeneous query statements to MS Access JetEngine which is where such queries are executed. MS Access JetEngine does not support CASE function.
Rewrite query statement and replace CASE function with IIF function which is a supported function in Access.
Use Oracle DB Links and use a non-Heterogeneous query.
Download and install Toad Professional Trial Edition (Toad Data Point) available at:
A full listing of MS Access 2007 functions: