SQL for join table problem?

Question

hi morning,
my problem also haven find out the solution,can help me solve.
I got one part of register student to exam,during that part is like that.
Student Code:________(table3)
Exam Code:_________(table 3)
Student Name:________(table 1)
Exam Name:_________(table 2)
I can write code call table 3 but when three table join together in part 3,got problem is come out alry....The problem is inside the Student Name & Exam Name.When i use the button for NEXTRECORD to check record,cannot call the student Name & exam Name.
Thank for help. Because i use sql code to call table 3 to check table1 and table 2 detail ,then retrive that data.
my code is like that,
private void cmd_NexRec_RSEActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
int i;
i=0;
try{
String x1,x2;
x1=(jTextField10.getText()).trim();
x2=(jTextField11.getText()).trim();
if (x1.equals("")&& x2.equals("") )
counter.studentExam="R";
counter.registerStudentExam="N";
i++;
jInternalFrame8.setVisible(false);
Connection con = getConnection2();
Statement s = con.createStatement (ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_UPDATABLE);
ResultSet rs=getStudentExams();
ResultSet rs1=getCodes();
ResultSet rs2=getExams();
String select="select * from studentExamFile a LEFT JOIN {studentData b} ON a.student_code=b.student_code LEFT JOIN {exam c} ON c.exam_code=a.exam_code where student_code='"+ x1 +"' and exam_code='"+ x2 +"'" ;
// String select ="select * from studentExamFile , exam , studentData where studentExamFile.student_code=studentData.student_code and exam.exam_code=studentExamFile.exam_code ";
// rs = s.executeQuery(select);
rs.next();
StudentExam c=getstudentcode(rs);
Code c1=getCode(rs1);
Examcode c2=getexamcode(rs2);
jTextField12.setText(c.studentcode);
jTextField13.setText(c.examcode);
jTextField14.setText(rs.getString("c1.name"));
jTextField15.setText(rs.getString("c2.ename"));
// jTextField14.setText(c1.name);
// jTextField14.setText(c2.ename);
jLabel16.setText("Record: Review");
jInternalFrame10.setVisible(true);
jTextField12.setEnabled(false);
jTextField13.setEnabled(false);
//New Line
jTextField14.requestFocus();
else
Connection con = getConnection2();
Statement s = con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_UPDATABLE);
String w=(jTextField10.getText()).trim();
String w2=(jTextField11.getText()).trim();
//String select= "select * from [studentExamFile] where [student_code]>'" w "'";
// String select1="select * from [studentExamFile] where [exam_code]>'" w2 "'";
String select="select * from studentExamFile a LEFT JOIN {studentData b} ON a.student_code=b.student_code LEFT JOIN {exam c} ON c.exam_code=a.exam_code where student_code='"+ x1 +"' and exam_code='"+ x2 +"'" ;
ResultSet rs;
rs = s.executeQuery(select);
// rs = s.executeQuery(select1);
rs.next();
if(rs.isFirst())
counter.registerStudentExam="N";
jInternalFrame8.setVisible(false);
jTextField12.setText(rs.getString(1));
jTextField13.setText(rs.getString(2));
jLabel16.setText("Record: Review");
jInternalFrame10.setVisible(true);
jTextField12.setEnabled(false);
jTextField13.setEnabled(false);
//New Line
jTextField14.requestFocus();
counter.studentExam="R";
else
JOptionPane.showMessageDialog(this,"End of the file ","Infomation",JOptionPane.INFORMATION_MESSAGE);
}catch(SQLException e)
System.out.println("Error");
//jTextField3.requestFocus();
}

Answer 1

thanks for reply.
i think my problem is in connection to database .
String sql="select studentData.student_name, exam.exam_name from studentData,exam,studentExamFile where studentData.student_code=studentExamFile.student_code and exam.exam_code=studentExamFile.exam_code ";
                // String sql="select studentData.student_name , exam.exam_name from studentExamFile  LEFT JOIN { studentData }  ON studentExamFile.student_code=studentData.student_code LEFT JOIN { exam }  ON exam.exam_code=studentExamFile.exam_code ";
                 Connection con = getConnection();
                 Statement s = con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_UPDATABLE);
                 Connection con2 = getConnection();
                 Statement s3 = con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_UPDATABLE);
                 System.out.println("error");//my problem inside here....help me
                 rs3=s.executeQuery(sql);
                 rs3=s3.executeQuery(sql);
                 rs3.next();
                 String s1,s2;
                 s1=rs3.getString(1);//maybe me dunno how to convert the sql data...
                 s2=rs3.getString(2);
                 rs.next();
                 rs2.next();
                // rs3.next();
                 Code c=getCode(rs);
                 Examcode c2=getexamcode(rs2);
                 StudentExam c3=getstudentcode(rs3);
                 jTextField12.setText(c3.studentcode);
                 jTextField13.setText(c3.examcode);
                // jTextField14.setText(rs.getString("c.name")); 
                 //jTextField15.setText(rs.getString("c2.ename"));
                 jTextField14.setText(s1); 
                 jTextField15.setText(s2);
                 jLabel16.setText("Record: Review");
                 jInternalFrame10.setVisible(true);
                 jTextField12.setEnabled(false);
                 //New Line
                 jTextField14.requestFocus();