ORA-01110: data file 6: Database not open and can't find the path of data file ""

Reason: Sometimes by mistake you have deleted the DBF files and while accessing the database you get the following exception:

ORA-01110: data file 6: Database not open. Can't find the path of data file "C:\oraclexe\xe\oradata\weblogic_Data01.DBF"

Solution:

offline drop of datafile:
In Oracle if you wish to delete DBF file and tablespace or schema you run the drop command to delete tablespace and physically remove the DBF file from the disk.
But sometimes you don't need to physically remove the file and just delete the tablespace offline i.e. Oracle will not access the tablespace or DBF file anymore but the file is still on the disk.

In the above problem, you have deleted the physical DBF file from the disk but oracle is still accessing that DBF file. In that case delete the DBF file offline by running the following command:

alter database datafile 'C:\oraclexe\xe\oradata\weblogic_Data01.DBF' offline drop;

then restart the database.

Note: Offlining of datafile is used when you have to delete the tablespace and also you can recover the data file on later date.