dbhomework.java.bak

java数据库学生管理系统 java数据库学生管理系统

		t=new Table(rset,"查询9",vec);
		t.setVisible(true);
	}
	catch(Exception e )
	{}
    }//GEN-LAST:event_jButton9ActionPerformed

    private void jButton8ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton8ActionPerformed
        //请在此处增加您的处理代码：
        //修改jTextField1，jTextField2的代码
        jTextField1.setText("8:查询缺成绩的学生的姓名、缺成绩的课程号及其学分数");
        jTextField2.setText("select sname, course.cno,credit from student,course,sc where student.sno=sc.sno and course.cno=sc.cno and grade is not null");
        //生成Table窗口
        Vector vec =new Vector(3);
        vec.addElement("姓名");
        vec.addElement("缺成绩的课程号");
        vec.addElement("学分数");
       try
	{
		stmt=con.createStatement();
		rset=stmt.executeQuery("SELECT sname, course.cno, credit "
				            + "FROM student, course, sc "
				            + "WHERE student.sno = sc.sno AND course.cno = sc.cno "
				            + "AND grade IS NULL;");
		t=new Table(rset,"查询8",vec);
		t.setVisible(true);
	}
	catch(Exception e )
	{}
    }//GEN-LAST:event_jButton8ActionPerformed

    private void jButton7ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton7ActionPerformed
        //请在此处增加您的处理代码：
        //修改jTextField1，jTextField2的代码
        jTextField1.setText("7:查询所有课程的成绩都在80分以上的学生的姓名、学号、且按学号升序排列");
        jTextField2.setText("select sname,sno from student where not exists (select * from sc where (sc.sno=student.sno) and(sc.grade<=80 or sc.grade is null)) order by sno asc ");
        //生成Table窗口
        Vector vec =new Vector(2);
        vec.addElement("姓名");
        vec.addElement("学号");
       try
	{
		stmt=con.createStatement();
		rset=stmt.executeQuery("select sname,sno from student where not exists (select * from sc where (sc.sno=student.sno) and(sc.grade<=80 or sc.grade is null)) order by sno asc " );
		t=new Table(rset,"查询7",vec);
		t.setVisible(true);
	}
	catch(Exception e )
	{}
    }//GEN-LAST:event_jButton7ActionPerformed

    private void jButton6ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton6ActionPerformed
        //请在此处增加您的处理代码：
        //修改jTextField1，jTextField2的代码
        jTextField1.setText("6:查询每门课程选课的学生人数、最高成绩、最低成绩和平均成绩");
        jTextField2.setText("select cno,count(sno),max(grade),min(grade),avg(grade) from sc group by cno");
        //生成Table窗口
        Vector vec =new Vector(5);
        vec.addElement("课程号");
        vec.addElement("学生人数");
        vec.addElement("最高成绩");
        vec.addElement("最低成绩");
        vec.addElement("平均成绩");
       try
	{
		stmt=con.createStatement();
		rset=stmt.executeQuery("select cno, count(sno),max(grade),min(grade),avg(grade) from sc group by cno" );
		t=new Table(rset,"查询6",vec);
		t.setVisible(true);
	}
	catch(Exception e )
	{}
    }//GEN-LAST:event_jButton6ActionPerformed

    private void jButton5ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton5ActionPerformed
        //请在此处增加您的处理代码：
         //修改jTextField1，jTextField2的代码
        jTextField1.setText("5:查询每位学生已选修课程的门数和总平均成绩");
        jTextField2.setText("select sno, count(cno),avg(grade) from sc group by sno");
        //生成Table窗口
        Vector vec =new Vector(3);
        vec.addElement("学号");
        vec.addElement("选课门数");
        vec.addElement("总平均成绩");
       try
	{
		stmt=con.createStatement();
		rset=stmt.executeQuery("select sno, count(cno),avg(grade) from sc group by sno" );
		t=new Table(rset,"查询5",vec);
		t.setVisible(true);
	}
	catch(Exception e )
	{}
    }//GEN-LAST:event_jButton5ActionPerformed

    private void jButton4ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton4ActionPerformed
        //请在此处增加您的处理代码：
         //修改jTextField1，jTextField2的代码
        jTextField1.setText("4:查询至少选修一门电机系课程的女生的姓名");
        jTextField2.setText("select sname from student where sno in (select sno from sc where sc.cno like 'ee%') and sex='女'");
        //生成Table窗口
        Vector vec =new Vector(1);
        vec.addElement("姓名");
       try
	{
		stmt=con.createStatement();
		rset=stmt.executeQuery("select sname from student where sno in (select sno from sc where sc.cno like 'ee%') and sex='女'" );
		t=new Table(rset,"查询4",vec);
		t.setVisible(true);
	}
	catch(Exception e )
	{}
    }//GEN-LAST:event_jButton4ActionPerformed

    private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton3ActionPerformed
        //请在此处增加您的处理代码：
        //修改jTextField1，jTextField2的代码
        jTextField1.setText("3:查询选修计算机系所开课程的男生的姓名、课程号、学分数、成绩");
        jTextField2.setText("select sname, course.cno, credit, grade from student, course, sc where course.cno like 'cs%' and course.semester = '秋' and student.sex = '男' and sc.sno = student.sno and sc.cno = course.cno");
        //生成Table窗口
        Vector vec =new Vector(4);
        vec.addElement("姓名");
        vec.addElement("课程号");
        vec.addElement("学分数");
        vec.addElement("成绩");
       try
	{
		stmt=con.createStatement();
		rset=stmt.executeQuery("select sname, course.cno, credit, grade from student, course, sc where course.cno like 'cs%' and course.semester = '秋' and student.sex = '男' and sc.sno = student.sno and sc.cno = course.cno");
		t=new Table(rset,"查询3",vec);
		t.setVisible(true);
	}
	catch(Exception e )
	{}
    }//GEN-LAST:event_jButton3ActionPerformed

    private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton2ActionPerformed
        //请在此处增加您的处理代码：
        //修改jTextField1，jTextField2的代码
        jTextField1.setText("2:查询计算机系秋季所开课程的课程号和学分数");
        jTextField2.setText("select cno,credit from course where (cno like 'cs%') and (semester='秋')");
        //生成Table窗口
        Vector vec =new Vector(2);
        vec.addElement("课程号");
        vec.addElement("学分数");
       try
	{
		stmt=con.createStatement();
		rset=stmt.executeQuery("select cno,credit from course where (cno like 'cs%') and (semester='秋')" );
		t=new Table(rset,"查询2",vec);
		t.setVisible(true);
	}
	catch(Exception e )
	{}
    }//GEN-LAST:event_jButton2ActionPerformed

    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton1ActionPerformed
        //请在此处增加您的处理代码：
        //修改jTextField1，jTextField2的代码
        jTextField1.setText("1:查询身高大于1.80米的男生的学号和姓名");
        jTextField2.setText("select sno ,sname from student where (height>1.80) and (sex='男')");
        //生成Table窗口
        Vector vec =new Vector(2);
        vec.addElement("学号");
        vec.addElement("姓名");
       try
	{
		stmt=con.createStatement();
		rset=stmt.executeQuery("select sno ,sname from student where (height>1.80) and (sex='男')" );
		t=new Table(rset,"查询1",vec);
		t.setVisible(true);
	}
	catch(Exception e )
	{}
    }//GEN-LAST:event_jButton1ActionPerformed
    
    /** Exit the Application */
    private void exitForm(java.awt.event.WindowEvent evt) {//GEN-FIRST:event_exitForm
        System.exit(0);
    }//GEN-LAST:event_exitForm
    
    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        new DBHomework().show();
    }
    
    
    // 变量声明 - 不进行修改//GEN-BEGIN:variables
    private javax.swing.JButton jButton1;
    private javax.swing.JButton jButton10;
    private javax.swing.JButton jButton2;
    private javax.swing.JButton jButton3;
    private javax.swing.JButton jButton4;
    private javax.swing.JButton jButton5;
    private javax.swing.JButton jButton6;
    private javax.swing.JButton jButton7;
    private javax.swing.JButton jButton8;
    private javax.swing.JButton jButton9;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JTextField jTextField1;
    private javax.swing.JTextField jTextField2;
    // 变量声明结束//GEN-END:variables
    private Table t;
    private Connection con;
    private Statement stmt;
    private ResultSet rset;
}