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ORA-54013: INSERT operation disallowed on virtual columns

Because the value of virtual columns is calcualated, it's not possible to insert (or update) theirs values.
The following attampt to update a virtual column and demonstrates that doing so throws the error message ORA-54013: INSERT operation disallowed on virtual columns:
create table tq84_tab (
   num_1   number,
   num_2   number,
   sum_    as (num_1 + num_2)
);

insert into tq84_tab values (1, 2, 3);

-- Cleaning up:

drop table tq84_tab;

See also

Other Oracle error messages such as
Identifying Virtual Columns in Oracle's Data Dictionary

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