you need to change the method accept additional parameters
public static void insertStudent(string personID, string studentNumber,string gradePointAverage , string majorFieldt)
Note that you need to give correct type based on column data type you given n database for related parameter. for example if personID is integer in database you should change parameter as int personID
change your sql statement with all the parameters
INSERT INTO student(personID, studentNumber, gradePointAverage , majorField ) VALUES (@personID, @studentNumber, @gradePointAverage , @majorField)
and set the parameter values using
cmd.Parameters.AddWithValue("@personID", personID);
cmd.Parameters.AddWithValue("@studentNumber", studentNumber);
cmd.Parameters.AddWithValue("@gradePointAverage", gradePointAverage );
cmd.Parameters.AddWithValue("@majorField", majorField );
you can call above method as below
private void btnInsertStudentNumberAdmin_Click(object sender, EventArgs e)
{
studentHelperClass.insertStudent(txtInsertStudentNumber.Text, txtstudentNumber.Text, txtgradePointAverage.Text , txtmajorField.Text );
}