Inserting data from one table to another | mysql

Question

I'm currently learning vb.net and I'm working on a little test project. Thing is, I have five tables:

Login, where I keep login information for students:

IDUser | Name | Surname | Username   | Password
---------------------------------------------
1      | John | Smith   | john.smith | john123

Students, where I keep basic informations about students

IDStudent | Name | Surname
--------------------------
1         | John | Smith 

Professors, where I keep basic informations about professors

IDProfessor | Name | Surname 
----------------------------
1           | Mike | Petersen

Subjects, where I keep basic information about subjects

IDSubject | SubjectName | ProfessorName
---------------------------------------
1         | Programming | Gary Williams

and for a final table, in which I need to insert data from tables above, I have Courses:

IDCourse | StudentID | SubjectID | ProfessorID
----------------------------------------------
1        | ??        | ???       | ????

The question is, how do I insert data in Course table from tables above. I'm currently using MySql as my database, and I've created foreign keys and connected them with the primary keys. I also have a ComboBox (filled with subjects from Subjects table) where a student can choose a Subject and by pressing the button, insert it in a Courses table.

Answer 1

Use DataTable s for each table and insert table data from one to another.For example :

 Dim con as new MySqlConnection="connectionsstringhere"
 con.open
 Dim cmd as new Mysqlcommand = "Select * from Login",con)

 dim table as new datatable
 Dim adapter as new mysqldataadapter(cmd)
 adapter.filll(table)
 Dim cmd2 as new mysqlcommand("Insert into Courses([student id],[subject id],[Professor id])values(@sid,@sbid,@pid)",con)
 cmd2.parametres.add("@sid",mysqldbtype.nvarchar).Value = table.rows(0)(1)  'here (0) is the column no. and (1) is the cell no.

   cmd2.parametres.add("@sbid",mysqldbtype. nvarchar).Value = table.rows(0)(2)  
 cmd2.executenonquery
 con.close

The following code will insert Login table's first 2 cells' data in Courses table.

Note that this is just a basic example.You need to modify the code based on your requirements

UPDATE I must've added this yesterday but i was a bit busy...However let's begin....

For each column in each tables,you can create a list(of string) .For example,create a list(of string) sub/variable named StudentnameandID .. Now, use a datatable for the first two tables(Student and Professor).Pass the values of cell 1 from the datatable to the List(of string) sub STUDENTNAMEANDID Make sure you add a special character like a comma(,) after every value...Then finally you can separate each value from Studentnameandid aas you've added commas... Then for each value in Studentnameandid , you add data to your last table.....

If you want a sample code for this,leave a comment and i'll add it