This is what i have so far. i need help resolving some and want to verify the others

1. Display all information about all courses that have no prerequisite

--SELECT * FROM COURSE WHERE PREREQUISITE IS NULL

2. Add yourself as a new student to the Student table (use sequence STUDENT_ID_SEQ.NEXTVAL as Student_ID and 07070 as zip)

--

3. List all students (display Student_ID, first name and last name) who live in zip 07070

--SELECT STUDENT_ID, FIRST_NAME, LAST_NAME FROM Student WHERE ZIP = '07070';

4. Show how many students who have phone area code 212 (HINT: use the SUBSTR function)

--SELECT COUNT(*) FROM Student WHERE SUBSTR(PHONE, 0, 3) = '212';

5. List all student names who work for Electronic Engineers and registered on or after Feb. 3, 2007

--SELECT FIRST_NAME, LAST_NAME FROM Student WHERE EMPLOYER = 'Electronic Engineers' AND REGISTRATION_DATE >= '2017-02-03';

6. List all courses that have "Intro to Information Systems" as prerequisite (HINT: use a subquery)

--

7. For all students who have phone area code 212, change the code to 202 while keeping the same phone number (HINT: consider using functions such as SUBSTR and LENGTH)

--

8. Delete your own student record added for query 2

-- Delete from student

Where first_name = danelle

9. Lower cost of all courses by 300

--UPDATE COURSE

SET COST = 300;

10. List all course costs (show course description and cost only) by the order of cost from lowest to highest (show courses without cost first)

--SELECT DESCRIPTION, COST

FROM COURSE

ORDER BY COST DESC;

The schema:

A P P E N D I X D STUDENT DATABASE SCHEMA ENR_SECT_FK ENR_STU_FK GR_ENR_FK GR_GRTW_FK GRTW_GRTYP_FK GRTW_SECT_FK INST_ZIP_FK SECT_CRSE_FK SECT_INST_FK STU_ZIP_FK CRSE_CRSE_FK ENROLLMENT STUDENT_ID (PK)(FK) NUMBER(8,0) NOT NULL SECTION_ID (PK)(FK) NUMBER(8,0) NOT NULL ENROLL_DATE DATE NOT NULL FINAL_GRADE NUMBER(3,0) NULL CREATED_BY VARCHAR2(30) NOT NULL CREATED_DATE DATE NOT NULL MODIFIED_BY VARCHAR2(30) NOT NULL MODIFIED_DATE DATE NOT NULL GRADE GRADE_CODE_OCCURRENCE (PK) NUMBER(38,0) NOT NULL STUDENT_ID (PK)(FK) NUMBER(8,0) NOT NULL SECTION_ID (PK)(FK) NUMBER(8,0) NOT NULL GRADE_TYPE_CODE (PK)(FK) CHAR(2) NOT NULL NUMERIC_GRADE NUMBER(3,0) NOT NULL COMMENTS VARCHAR2(2000) NULL CREATED_BY VARCHAR2(30) NOT NULL CREATED_DATE DATE NOT NULL MODIFIED_BY VARCHAR2(30) NOT NULL MODIFIED_DATE DATE NOT NULL GRADE_CONVERSION LETTER_GRADE (PK) VARCHAR2(2) NOT NULL GRADE_POINT NUMBER(3,2) NOT NULL MAX_GRADE NUMBER(3,0) NOT NULL MIN_GRADE NUMBER(3,0) NOT NULL CREATED_BY VARCHAR2(30) NOT NULL CREATED_DATE DATE NOT NULL MODIFIED_BY VARCHAR2(30) NOT NULL MODIFIED_DATE DATE NOT NULL GRADE_TYPE GRADE_TYPE_CODE (PK) CHAR(2) NOT NULL DESCRIPTION VARCHAR2(50) NOT NULL CREATED_BY VARCHAR2(30) NOT NULL CREATED_DATE DATE NOT NULL MODIFIED_BY VARCHAR2(30) NOT NULL MODIFIED_DATE DATE NOT NULL GRADE_TYPE_WEIGHT SECTION_ID (PK)(FK) NUMBER(8,0) NOT NULL GRADE_TYPE_CODE (PK)(FK) CHAR(2) NOT NULL NUMBER_PER_SECTION NUMBER(3,0) NOT NULL PERCENT_OF_FINAL_GRADE NUMBER(3,0) NOT NULL DROP_LOWEST CHAR(1) NOT NULL CREATED_BY VARCHAR2(30) NOT NULL CREATED_DATE DATE NOT NULL MODIFIED_BY VARCHAR2(30) NOT NULL MODIFIED_DATE DATE NOT NULL INSTRUCTOR INSTRUCTOR_ID (PK) NUMBER(8,0) NOT NULL SALUTATION VARCHAR2(5) NULL FIRST_NAME VARCHAR2(25) NULL LAST_NAME VARCHAR2(25) NULL STREET_ADDRESS VARCHAR2(50) NULL PHONE VARCHAR2(15) NULL CREATED_BY VARCHAR2(30) NOT NULL CREATED_DATE DATE NOT NULL MODIFIED_BY VARCHAR2(30) NOT NULL MODIFIED_DATE DATE NOT NULL ZIP (FK) VARCHAR2(5) NULL SECTION SECTION_ID (PK) NUMBER(8,0) NOT NULL SECTION_NO NUMBER(3,0) NOT NULL START_DATE_TIME DATE NULL LOCATION VARCHAR2(50) NULL CAPACITY NUMBER(3,0) NULL CREATED_BY VARCHAR2(30) NOT NULL CREATED_DATE DATE NOT NULL MODIFIED_BY VARCHAR2(30) NOT NULL MODIFIED_DATE DATE NOT NULL COURSE_NO (FK) NUMBER(8,0) NOT NULL INSTRUCTOR_ID (FK) NUMBER(8,0) NOT NULL STUDENT STUDENT_ID (PK) NUMBER(8,0) NOT NULL SALUTATION VARCHAR2(5) NULL FIRST_NAME VARCHAR2(25) NULL LAST_NAME VARCHAR2(25) NOT NULL STREET_ADDRESS VARCHAR2(50) NULL PHONE VARCHAR2(15) NULL EMPLOYER VARCHAR2(50) NULL REGISTRATION_DATE DATE NOT NULL CREATED_BY VARCHAR2(30) NOT NULL CREATED_DATE DATE NOT NULL MODIFIED_BY VARCHAR2(30) NOT NULL MODIFIED_DATE DATE NOT NULL ZIP (FK) VARCHAR2(5) NOT NULL ZIPCODE ZIP (PK) VARCHAR2(5) NOT NULL CITY VARCHAR2(25) NULL STATE VARCHAR2(2) NULL CREATED_BY VARCHAR2(30) NOT NULL CREATED_DATE DATE NOT NULL MODIFIED_BY VARCHAR2(30) NOT NULL MODIFIED_DATE DATE NOT NULL COURSE COURSE_NO (PK) NUMBER(8,0) NOT NULL DESCRIPTION VARCHAR2(50) NOT NULL COST NUMBER(9,2) NULL CREATED_BY VARCHAR2(30) NOT NULL CREATED_DATE DATE NOT NULL MODIFIED_BY VARCHAR2(30) NOT NULL MODIFIED_DATE DATE NOT NULL