Search notes:
ORA-00911: invalid character
Although the dollar sign, the underscore and numbers are permitted in identifiers, identifiers cannot start with these characters (except when quoted):
select _leading_underscore from dual ;
String literals need to be quoted:
create table tq84_xyz(
col varchar2(20)
);
insert into tq84_xyz values (#);
drop table tq84_xyz;
Special characters such as the greek μ which is commonly used to denote micro (as in microseconds) is not allowed in identifiers:
create table tq84_t (
time_µsecs number
);
If the μ needs to be in the column name, it can be quoted:
create table tq84_t (
"time_µsecs" number
);
See also
This error message is also thrown when trying to set a hidden init-parameter without quoting it.