SQL Error: ORA-01722: invalid number - oracle

Question

I have enclosed the table and the insert statement I am working on.
CREATE TABLE EMP (
DRIVER_ID INTEGER NOT NULL
, FNAME VARCHAR(30) NOT NULL
, LNAME VARCHAR(30) NOT NULL
, ADDRESS VARCHAR(50) NOT NULL
, SALARY VARCHAR(50) NOT NULL
, DOB DATE NOT NULL
, SHIFTS VARCHAR2(20) NOT NULL
, SSN CHAR(11) NOT NULL
, PHONE INTEGER NOT NULL
, HIRING_DATE DATE NOT NULL
, EMAIL VARCHAR2(50) NOT NULL
);
When I run this insert statement:
INSERT INTO EMP (DRIVER_ID, FNAME, LNAME, ADDRESS, SALARY, DOB, SHIFTS, SSN, PHONE, HIRING_DATE, EMAIL)
VALUES (SEQ_EMP.NEXTVAL,'Emma', 'Johnson', '123 Main Street', 'DIRECT DEPOSIT', '31 JANUARY,1988', 'MORNING', '579-45-6666', '410-555-1112', '16 DECEMBER,2013', 'ejohnson#fakemail.com');
I get this error message
SQL Error: ORA-01722: invalid number
01722. 00000 - "invalid number"
*Cause: The specified number was invalid.
*Action: Specify a valid number.

Answer 1

Lets look at this logically. The error message is saying "invalid number". Oracle is saying to you "I am expecting a number, but you gave me something that isn't a number".
Looking at the table SQL, you can see that the table has two columns whose type is a number type (actually INTEGER). These are DRIVER_ID and PHONE. (The other columns don't matter now ... because they won't expect a number as the value.)
Now look at the insert SQL, and the values corresponding to those columns.
The value inserted into the DRIVER_ID column comes from SEQ_EMP.NEXTVAL ... which I would assume has type INTEGER. That means, you won't get an error from there.
The value inserted into the PHONE column is '410-555-1112'. But, hey, that isn't a number. Its a string! And besides a (mathematical) number doesn't have hyphen characters embedded in it!
In short, if you are going to store phone numbers with - (or + or space) characters embedded in them, you can't use INTEGER as the column type.

Answer 2

In your table DDL change
PHONE INTEGER NOT NULL
to
PHONE CHAR(12) NOT NULL
as previously mentioned by user Stephen C using CHAR instead of INTEGER.
Also, those DATE fields will have to be converted to CHAR datatypes as well or you'll have to format your INSERT to handle the date format properly. Those fields are:
, DOB DATE NOT NULL
, HIRING_DATE DATE NOT NULL
If you chose to keep the columns as DATEs, then in your insert use (for the above-mentioned columns) the following...
,to_date('31-JANUARY-1988','DD-MONTH-YYYY')
,to_date('16-DECEMBER-2013','DD-MONTH-YYYY')
The above won't give you exactly what you are looking for -- e.g. 16 DECEMBER,2013 -- but it will work and format the date with hyphens -- e.g. 16-DECEMBER-2013. If you need further information on the to_date() function for Oracle for formatting and for other sundry information, please refer to the Oracle docs or search on "Oracle TO_DATE" via your favorite browser.
HTH