SQL error “ORA-01722: invalid number”

Question

A very easy one for someone, The following insert is giving me the

ORA-01722: invalid number

why?

INSERT INTO C         


        

Answer 1

Suppose telephone number is defined as NUMBER then the blanks cannot be converted into a number:

create table telephone_number (tel_number number);
insert into telephone_number values ('0419 853 694');

The above gives you a

ORA-01722: invalid number