when running :

/* Insert the data into the COURSE table */ INSERT INTO COURSE VALUES('ACCT-211','Accounting I',3); INSERT INTO COURSE VALUES('ACCT-212','Accounting II',3); INSERT INTO COURSE VALUES('CIS-220','Intro to Microcomputing',3); INSERT INTO COURSE VALUES('CIS-420','Database Design and Implementation',4);

/* Insert the data into the CLASS table */ INSERT INTO CLASS VALUES(10012,'ACCT-211',1,'MWF 8:00-8:50 a.m.','BUS311'); INSERT INTO CLASS VALUES(10013,'ACCT-211',2,'MWF 9:00-9:50 a.m.','BUS200'); INSERT INTO CLASS VALUES(10014,'ACCT-211',3,'TTh 2:30-3:45 p.m.','BUS252'); INSERT INTO CLASS VALUES(10015,'ACCT-212',1,'MWF 10:00-10:50 a.m.','BUS311'); INSERT INTO CLASS VALUES(10016,'ACCT-212',2,'Th 6:00-8:40 p.m.','BUS252'); INSERT INTO CLASS VALUES(10017,'CIS-220',1,'MWF 9:00-9:50 a.m.','KLR209'); INSERT INTO CLASS VALUES(10018,'CIS-220',2,'MWF 9:00-9:50 a.m.','KL211'); INSERT INTO CLASS VALUES(10019,'CIS-220',3,'MWF 10:00-10:50 a.m.','KLR209'); INSERT INTO CLASS VALUES(10020,'CIS-420',1,'W 6:00-8:40 p.m.','KLR209');

/* Insert the data into the STUDENT table */ INSERT INTO STUDENT VALUES(321421,'Bowser','William','C','1975-02-12',42,'So',2.84,2134); INSERT INTO STUDENT VALUES(324257,'Smithson','Anne','K','1981-11-15',81,'Jr',3.27,2256); INSERT INTO STUDENT VALUES(324258,'Brewer','Juliette',' ','1968-08-23',38,'So',2.26,2256); INSERT INTO STUDENT VALUES(324299,'Smith','John','B','1986-11-30',15,'Fr',2.92,2315);

/* Insert the data into the ENROLL table */ INSERT INTO ENROLL VALUES (10014,321452,'C'); INSERT INTO ENROLL VALUES (10014,324257,'B'); INSERT INTO ENROLL VALUES (10018,321452,'A'); INSERT INTO ENROLL VALUES (10018,324257,'B');

get multiple errors:

ORA-00001: unique constraint (SQL_YCCNBIDFWHMDBRHQIHQGKOLRZ.SYS_C0052064000) violated ORA-06512: at "SYS.DBMS_SQL", line 1721 ORA-00001: unique constraint (SQL_YCCNBIDFWHMDBRHQIHQGKOLRZ.SYS_C0052064000) violated ORA-06512: at "SYS.DBMS_SQL", line 1721 ORA-00001: unique constraint (SQL_YCCNBIDFWHMDBRHQIHQGKOLRZ.SYS_C0052064000) violated ORA-06512: at "SYS.DBMS_SQL", line 1721 ORA-00001: unique constraint (SQL_YCCNBIDFWHMDBRHQIHQGKOLRZ.SYS_C0052064000) violated ORA-06512: at "SYS.DBMS_SQL", line 1721 ORA-00942: table or view does not exist ORA-00942: table or view does not exist ORA-00942: table or view does not exist ORA-00942: table or view does not exist ORA-00942: table or view does not exist ORA-00942: table or view does not exist ORA-00942: table or view does not exist ORA-00942: table or view does not exist ORA-00942: table or view does not exist ORA-01861: literal does not match format string ORA-06512: at "SYS.DBMS_SQL", line 1721 ORA-01861: literal does not match format string ORA-06512: at "SYS.DBMS_SQL", line 1721 ORA-01861: literal does not match format string ORA-06512: at "SYS.DBMS_SQL", line 1721 ORA-01861: literal does not match format string ORA-06512: at "SYS.DBMS_SQL", line 1721 ORA-00942: table or view does not exist ORA-00942: table or view does not exist ORA-00942: table or view does not exist ORA-00942: table or view does not exist

how do I address: