What exactly you want means with this?
There no exists database lock mode.
If you want the default lock mode , this is not define on the database , is defined over the all instance in the ONCONFIG file with parameter DEF_TABLE_LOCKMODE.
by default the lock mode is PAGE lock.
Another parameter is the IFX_DEF_TABLE_LOCKMODE enviroment variable. This override the DEF_TABLE_LOCKMODE parameter on the ONCONFIG , but is valid only to the session where the variable is set.
to get the lock mode of each table , you can use the dbschema with -ss parameter.