c:\data\bitcoin-qt -wallet=c:\dir\wal\ -datadir=c:\btcdata\ 
and

    c:\data\bitcoin-qt -wallet=c:\dir\wal2\ -datadir=c:\btcdata2\ 

take error

    sqlitedatabase: unable to obtain an exclusive lock on the database is it being used by another instance of bitcoin core

how to use one database for multi sample clients with different wallets