i've made a sql to a data base project, i will give the project then the code and find the mistakes ABC Training Center

ABC is a training center that conducts various training courses. Each course is identified by a course no, title, units, level, and subject. Courses are conducted by instructors, who can be full time or part time. Instructors are identified by an identifier, name, mobile phone number, email, address comprising of street name, city and country, and specialty. An instructor’s employment status is determined at the time of appointment. Part time instructors work a number of hours each month and are paid according to a pay rate, which must be greater than 20, determined by the training center. Full time instructors have monthly salaries. In certain circumstances, full time instructors may be assigned additional training courses besides to their training load and they are paid as part time instructors. An instructor can train a group of students in one course for each training period. The same course may be conducted by several instructors at the same training periods. Each year is divided into 4 training periods. The starting and ending dates describe a training period. A student, described by an id, student number, name, address, at least one email, and age, may participate in up to 3 training courses per period. Students' information may be queried using first and last names.

The project consists of four phases:

1. Conceptual Design Phase:

In this phase, you are to develop an Enhanced Entity-Relationship (EER) diagram using UML notation for the database based on the information provided. If there are ambiguities, you must resolve them and state your assumptions. The EER diagram must conceptually model the data requirements of the enterprise.

2. Logical Design Phase In this phase, you must map the EER diagram into a set of relations with minimal nulls. Show primary keys and identify foreign keys.

3. Relations Normalization Phase In this phase, you must normalize your relational database design to the 3NF.

4. Database Implementation Phase In this phase, write SQL DDL statements that can be used to create the tables for the relations you obtained from phase (3) with sample data (an average of 3 rows per table). Write an SQL statement to list all instructors who are full time and worked on a part time basis in alphabetical order of names. Write an SQL statement to list all student names and their completed courses. CREATE TABLE Course ( CourseNo INT PRIMARY KEY, Title VARCHAR(255), Units INT, Level VARCHAR(50), Subject VARCHAR(100) );

CREATE TABLE Instructor ( ID INT PRIMARY KEY, Name VARCHAR(255), Mobile VARCHAR(20), Email VARCHAR(255), Address VARCHAR(255), Specialty VARCHAR(100), EmploymentStatus VARCHAR(20) );

CREATE TABLE Student ( ID INT PRIMARY KEY, StudentNo INT, Name VARCHAR(255), Address VARCHAR(255), Email VARCHAR(255), Age INT );

CREATE TABLE TrainingPeriod ( StartDate DATE PRIMARY KEY, EndDate DATE );

CREATE TABLE Teaches ( InstructorID INT, CourseNo INT, TrainingPeriod DATE, PRIMARY KEY (InstructorID, CourseNo, TrainingPeriod), FOREIGN KEY (InstructorID) REFERENCES Instructor(ID), FOREIGN KEY (CourseNo) REFERENCES Course(CourseNo), FOREIGN KEY (TrainingPeriod) REFERENCES TrainingPeriod(StartDate) );

CREATE TABLE Enrolls ( StudentID INT, CourseNo INT, TrainingPeriod DATE, PRIMARY KEY (StudentID, CourseNo, TrainingPeriod), FOREIGN KEY (StudentID) REFERENCES Student(ID), FOREIGN KEY (CourseNo) REFERENCES Course(CourseNo), FOREIGN KEY (TrainingPeriod) REFERENCES TrainingPeriod(StartDate) ); -- Create the Instructor table CREATE TABLE Instructor ( ID INT PRIMARY KEY, Name VARCHAR(100), Mobile VARCHAR(20), Email VARCHAR(100), Address VARCHAR(100), Specialty VARCHAR(50), EmploymentStatus VARCHAR(20) );

-- Insert sample data into the Instructor table INSERT INTO Instructor VALUES (1, 'Instructor1', '123-456-7890', '[email protected]', '123 Main St, City, Country', 'Specialty1', 'Full Time'); INSERT INTO Instructor VALUES (2, 'Instructor2', '987-654-3210', '[email protected]', '456 Oak St, City, Country', 'Specialty2', 'Part Time'); INSERT INTO Instructor VALUES (3, 'Instructor3', '555-123-4567', '[email protected]', '789 Pine St, City, Country', 'Specialty3', 'Full Time');

-- Create the Student table CREATE TABLE Student ( ID INT PRIMARY KEY, StudentNo INT, Name VARCHAR(100), Address VARCHAR(100), Email VARCHAR(100), Age INT );

-- Insert sample data into the Student table INSERT INTO Student VALUES (1, 1001, 'Student1', '101 Ram, City, Country', '[email protected]', 20); INSERT INTO Student VALUES (2, 1002, 'Student2', '202 Lakman, City, Country', '[email protected]', 22); INSERT INTO Student VALUES (3, 1003, 'Student3', '303 Sita, City, Country', '[email protected]', 25);

-- Create the TrainingPeriod table CREATE TABLE TrainingPeriod ( StartDate DATE PRIMARY KEY, EndDate DATE );

-- Insert sample data into the TrainingPeriod table INSERT INTO TrainingPeriod VALUES ('2023-01-01', '2023-04-01'); INSERT INTO TrainingPeriod VALUES ('2023-04-02', '2023-07-01'); INSERT INTO TrainingPeriod VALUES ('2023-07-02', '2023-10-01');

-- Create the Teaches table CREATE TABLE Teaches ( InstructorID INT, CourseNo INT, StartDate DATE, EndDate DATE, PRIMARY KEY (InstructorID, CourseNo, StartDate, EndDate), FOREIGN KEY (InstructorID) REFERENCES Instructor(ID), FOREIGN KEY (CourseNo) REFERENCES Course(CourseNo), FOREIGN KEY (StartDate, EndDate) REFERENCES TrainingPeriod(StartDate, EndDate) );

-- Insert sample data into the Teaches table INSERT INTO Teaches VALUES (1, 1, '2023-01-01', '2023-04-01'); INSERT INTO Teaches VALUES (2, 2, '2023-04-02', '2023-07-01'); INSERT INTO Teaches VALUES (3, 3, '2023-07-02', '2023-10-01');

-- Create the Enrolls table CREATE TABLE Enrolls ( StudentID INT, CourseNo INT, StartDate DATE, EndDate DATE, PRIMARY KEY (StudentID, CourseNo, StartDate, EndDate), FOREIGN KEY (StudentID) REFERENCES Student(ID), FOREIGN KEY (CourseNo) REFERENCES Course(CourseNo), FOREIGN KEY (StartDate, EndDate) REFERENCES TrainingPeriod(StartDate, EndDate) );

-- Insert sample data into the Enrolls table INSERT INTO Enrolls VALUES (1, 1, '2023-01-01', '2023-04-01'); INSERT INTO Enrolls VALUES (2, 2, '2023-04-02', '2023-07-01'); INSERT INTO Enrolls VALUES (3, 3, '2023-07-02', '2023-10-01');