ORA-02291: integrity constraint violated - parent key not found - oracle

Question

SO here is my Database:
CREATE TABLE courses (
ccode VARCHAR2(10) CONSTRAINT courses_PK PRIMARY KEY,
cname VARCHAR2(50),
coursefee NUMBER(6)
);
CREATE TABLE faculty (
fcode VARCHAR2(5) CONSTRAINT faculty_PK PRIMARY KEY,
name VARCHAR2(50)
);
CREATE TABLE batches (
bcode varchar2(5) CONSTRAINT batches_PK PRIMARY KEY,
ccode varchar2(5) CONSTRAINT batches_ccode_FK REFERENCES COURSES(ccode),
fcode varchar2(5) CONSTRAINT batches_fcode_FK REFERENCES FACULTY(fcode),
stdate date CONSTRAINT batches_stdate_nn not null,
enddate date,
timing number(1) CONSTRAINT batches_timing_chk check( timing in (1,2,3) ),
CONSTRAINT batches_date_chk check ( stdate <= enddate)
);
CREATE TABLE students (
rollno number(5) CONSTRAINT students_PK PRIMARY KEY,
bcode varchar2(5) CONSTRAINT students_bcode_FK REFERENCES batches(bcode),
name varchar2(30),
gender char(1) CONSTRAINT students_gender_chk check( upper(gender) in ('M','F')),
dj date,
phone varchar2(10),
email varchar2(30)
);
Insert Table:
INSERT INTO batches VALUES('A0001','A0016','A0031','08-05-13','08-06-17',1);
INSERT INTO batches VALUES('B0002','E0017','B0032','08-05-13','08-06-26',2);
INSERT INTO batches VALUES('C0003','C0018','C0033','08-06-27','08-06-28',2);
INSERT INTO batches VALUES('D0004','D0019','D0034','08-06-27','08-08-11',3);
INSERT INTO batches VALUES('E0005','E0020','E0035','08-07-01','08-08-09',2);
INSERT INTO batches VALUES('F0006','F0021','F0036','08-07-21','08-08-11',1);
INSERT INTO batches VALUES('G0007','V0022','G0037','08-08-31','08-09-21',3);
INSERT INTO batches VALUES('H0008','H0023','H0038','08-09-17','08-10-14',3);
INSERT INTO batches VALUES('I0009','I0024','I0039','08-09-23','08-10-20',2);
INSERT INTO batches VALUES('J0010','P0025','J0040','08-10-04','08-11-26',1);
INSERT INTO batches VALUES('K0011','F0026','K0041','08-10-10','08-11-17',2);
INSERT INTO batches VALUES('L0012','C0027','L0042','08-11-02','09-02-23',2);
INSERT INTO batches VALUES('M0013','M0028','M0043','08-12-09','09-01-02',3);
INSERT INTO batches VALUES('N0014','N0029','N0044','08-12-11','09-01-08',3);
INSERT INTO batches VALUES('O0015','O0030','O0045','08-12-15','09-01-12',2);
INSERT INTO students VALUES(001,'A0001','Andrew Johnson','M','08-01-10','677-0323','AndyJ#hotmail.com');
INSERT INTO students VALUES(002,'B0002','Dionne Peterson','F','08-01-10','324-9705','dionnepet#gmail.com');
INSERT INTO students VALUES(003,'C0003','Sydney Peters','F','08-01-10','624-9664','SydersP#yahoo.com');
INSERT INTO students VALUES(004,'D0004','Tsian Figaro','F','08-09-01','310-4957','tsianfigaro#hotmail.com');
INSERT INTO students VALUES(005,'E0005','Jewel Forbes','F','08-09-01','666-5948','Jewel#gmail.com');
INSERT INTO students VALUES(006,'F0006','Jason Fitzpatrick','M','08-01-02','657-4958','JasonFitz#hotmail.com');
INSERT INTO students VALUES(007,'G0007','Ali Maharaj','M','08-01-02','674-4437','AliMaharaj#gmail.com');
INSERT INTO students VALUES(008,'H0008','Mariah Sunderstone','F','08-01-02','707-4056','mariahS#yahoo.com');
INSERT INTO students VALUES(009,'I0009','Ariah Baron','F','08-01-02','673-9685','AriBar#yahoo.com');
INSERT INTO students VALUES(010,'J0010','Joe Zheng ','M','08-09-01','348-4567','Zhengdo#hotmail.com');
INSERT INTO students VALUES(011,'K0011','Donald Yen','M','08-09-01','328-4749','DonnieYen#gmail.com');
INSERT INTO students VALUES(012,'L0012','Jackson Chang','M','08-08-27','345-6847','JackieChang#yahoo.com');
INSERT INTO students VALUES(013,'M0013','Scott Smith','M','08-01-02','702-9903','Scottsmith#hotmail.com');
INSERT INTO students VALUES(014,'N0014','Michelle Shareef','F','08-02-27','321-0589','michelleShareef#gmail.com');
INSERT INTO students VALUES(015,'O0015','Jean Louis Pierre ','M','08-09-01','428-8378','JLPierre#gmail.com');
The error that keeps coming up for batches Table is :
ORA-02290: check constraint (EJAY.BATCHES_DATE_CHK) violated
ANd the error that comes up for students Table is:
ORA-02291: integrity constraint violated - parent key not found
What I'm confused about is that it only shows up for some rows in the tables. faculty and courses are fine, it's just these two.
If the answers is obvious, I apologize, I'm a beginner. Please help

Answer 1

Insert in Batches is failing because you have your dates mixed up; they're dd-mm-yy.
For example, INSERT INTO batches VALUES('D0004','D0019','D0034','08-06-27','08-08-11',3); fails the test stdate <= enddate.
The insert in Students is failing because you're referring to a value in Batches that does not exist (because the inserts failed?).