Split MySQL and compare it - mysql

Question

I have a problem that I don't know how to resolve it, I am a begginer in SQL.
I want to display the first name of all students that have the same FirstName as the teachers name, In the database the teacher's name is a single field but contains 2 logical fields ( FirstName and LastName)
This is my database format
CREATE TABLE Faculty (
Id INT NOT NULL PRIMARY KEY AUTO_INCREMENT
,NAME VARCHAR(50)
,Address VARCHAR(60)
,YearFounded YEAR
,Dean VARCHAR(50)
);
CREATE TABLE Specialty (
Id INT NOT NULL PRIMARY KEY auto_increment
,IdFaculty INT (11) NOT NULL
,NAME VARCHAR(50)
,FOREIGN KEY (IdFaculty) REFERENCES Faculty(Id)
);
CREATE TABLE Course (
Id INT NOT NULL PRIMARY KEY auto_increment
,IdSpecialty INT NOT NULL
,NAME VARCHAR(50)
,TeachingYear INT
,Semester INT
,Professor VARCHAR(50)
,< -- TEACHER
FOREIGN KEY (IdSpecialty) REFERENCES Specialty(Id)
);
CREATE TABLE Student (
Id INT NOT NULL PRIMARY KEY auto_increment
,< -- STUDENT
IdFaculty INT NOT NULL
,IdSpecialty INT NOT NULL
,CurrentYear INT
,StudyGroup VARCHAR(10)
,Semester INT
,Scholarship VARCHAR(2)
,FOREIGN KEY (IdFaculty) REFERENCES Faculty(Id)
,FOREIGN KEY (IdSpecialty) REFERENCES Specialty(Id)
);
CREATE TABLE StudentData (
Id INT NOT NULL PRIMARY KEY
,CNP CHAR(13)
,FirstName VARCHAR(30)
,LastName VARCHAR(30)
,Father VARCHAR(50)
,Mother VARCHAR(50)
,Address VARCHAR(200)
,Nationality VARCHAR(50)
);
CREATE TABLE Grade (
Id INT NOT NULL PRIMARY KEY auto_increment
,IdStudent INT NOT NULL
,IdCourse INT NOT NULL
,Grade INT
,ExamDate DATE
,FOREIGN KEY (IdStudent) REFERENCES Student(Id)
,FOREIGN KEY (IdCourse) REFERENCES Course(Id)
);

Answer 1

Considering that Course.Professor field contains the professor firstname and lastname, I would use this query :
select sd.FirstName from StudentData sd
LEFT JOIN Student s on sd.Id = s.Id
LEFT JOIN Specialty special on s.IdSpecialty = special.Id
LEFT JOIN Course c on special.Id = c.IdSpecialty
WHERE c.Professor = CONCAT(sd.FirstName, ' ', sd.LastName)
EDIT:
If you only want students that have the same FirstName (not lastname) as the professor and if the professor field contains values like "Jacques Dupont" (for example) where Jacques is FirstName and Dupont is LastName then try this (using SUBSTRING_INDEX function to get the professor's FirstName):
select sd.FirstName from StudentData sd
LEFT JOIN Student s on sd.Id = s.Id
LEFT JOIN Specialty special on s.IdSpecialty = special.Id
LEFT JOIN Course c on special.Id = c.IdSpecialty
WHERE SUBSTRING_INDEX(c.Professor,' ',1) = sd.FirstName