ORA-06553: PLS-221: 'name' is not a procedure or is undefined

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This type of parsing error is quickly explained:

select dbms_db_version.version from dual;

SQL Error: ORA-06553: PLS-221: 'VERSION' is not a procedure or is undefined

In the example above dbms_db_version.version is not a packaged function, but a packaged constant.
Packaged constants can be used inside PL/SQL procedures but not inside ordinary SQL statements, however you can specify such constants in SQL DML statements inside programs:

declare
  v number;
begin
  select dbms_db_version.version into v
    from dual;
  dbms_output.put_line(v);
end;
/

If you need to specify constants inside DML statements such as SELECT/DELETE/INSERT/UPDATE statements, then you can create wrapping functions as follows:

create or replace function db_version
return integer deterministic
is
begin
return dbms_db_version.version;
end;

select db_version from dual;

DB_VERSION
-------------
10

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