Oracle sql problem

Question

hello!
PROBLEM 1: how do you drop foreign key constraint without constraint name?
PROBLEM 2:i created two tables employee and department.
CREATE TABLE EMPLOYEE
FNAME VARCHAR (25) NOT NULL,
MINIT VARCHAR(10),
LNAME VARCHAR(25) NOT NULL,
SSN CHAR(9),
BDATE DATE,
ADDRESS VARCHAR(30),
SEX CHAR,
SALARY DECIMAL(10,2),
SUPERSSN CHAR(9),
DNO INT,
PRIMARY KEY (SSN),
FOREIGN KEY (SUPERSSN) REFERENCES EMPLOYEE(SSN)
CREATE TABLE DEPARTMENT
DNAME VARCHAR(25),
DNUMBER INT NOT NULL,
MGRSSN CHAR(9),
MGRSTARTDATE DATE,
PRIMARY KEY(DNUMBER),
FOREIGN KEY(MGRSSN) REFERENCES EMPLOYEE(SSN)
ALTER TABLE EMPLOYEE ADD FOREIGN KEY (DNO) REFERENCES DEPARTMENT(DNUMBER);
i then made DNO foreign key.
when i was trying to enter values
INSERT INTO EMPLOYEE
VALUES ('john','b','smith',123456789,'1965-01-09','731 fondren, houston,tx','m',30000,'333445555',5);
it shows this error
ORA-01722: invalid number
why it is showing me this error and how do i fix it?
thanks.

Answer 1

Hi User,
Solution 1 :
SELECT * FROM USER_CONSTRAINTS WHERE table_name ='EMPLOYEE';
ALTER TABLE employee DROP CONSTRAINT SYS_C0010744;Solution 2 :
INSERT INTO employee
            (fname, minit, lname, ssn,
             bdate, address, salary,
             superssn, dno
     VALUES ('john', 'b', 'smith', 123456789,
             TO_DATE ('1965-01-09', 'YYYY-MM-DD'), '731 fondren', 30000,
             123456789, 30000
            );Thanks,
Shankar