2023.5.30每日总结

 public examination[] sortAll2()throws Exception
    {
        String sql="select count(*) from examination where grade <60";
        PreparedStatement pre = connect.prepareStatement(sql,ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);//改成可以改位置
        ResultSet rs = pre.executeQuery();
        rs.last();//光标移到最后
        int rowCount=rs.getRow();//当前行是第几行
        rs.beforeFirst();//移回去
        examination[] examinations=new examination[rowCount];
        int i=0;
        while(rs.next())
        {
            examinations[i]=new examination();
            examinations[i].stuid=rs.getString("stuid");
            examinations[i].examname=rs.getString("examname");
            examinations[i].grade=rs.getInt("grade");
            i++;
        }
        pre.close();
        return examinations;
    }
    public examination[] sortAll()throws Exception
    {
        String sql="select count(*) from examination where grade >89";
        PreparedStatement pre = connect.prepareStatement(sql,ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);//改成可以改位置
        ResultSet rs = pre.executeQuery();
        rs.last();//光标移到最后
        int rowCount=rs.getRow();//当前行是第几行
        rs.beforeFirst();//移回去
        examination[] examinations=new examination[rowCount];
        int i=0;
        while(rs.next())
        {
            examinations[i]=new examination();
            examinations[i].stuid=rs.getString("stuid");
            examinations[i].examname=rs.getString("examname");
            examinations[i].grade=rs.getInt("grade");
            i++;
        }
        pre.close();
        return examinations;
    }
    public examination[] searchAll(String stuid,String examname,String teaid)throws Exception
    {
        String sql="select * from examination where stuid like ? and examname like ? and teaid=?";
        PreparedStatement pre = connect.prepareStatement(sql,ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);//改成可以改位置
        pre.setString(1,"%"+stuid+"%");
        pre.setString(2,"%"+examname+"%");
        pre.setString(3,teaid);
        ResultSet rs = pre.executeQuery();
        rs.last();//光标移到最后
        int rowCount=rs.getRow();//当前行是第几行
        rs.beforeFirst();//移回去
        examination[] examinations=new examination[rowCount];
        int i=0;
        while(rs.next())
        {
            examinations[i]=new examination();
            examinations[i].stuid=rs.getString("stuid");
            examinations[i].examname=rs.getString("examname");
            examinations[i].grade=rs.getInt("grade");
            i++;
        }
        pre.close();
        return examinations;

    }
    public boolean ModifyTeacher(String teaid,String teaname,String teapwd)throws Exception
    {
        String sql="update teacher set teaname=?,teapwd=? where teaid=?";
        PreparedStatement pre = connect.prepareStatement(sql);
        pre.setString(1,teaname);
        pre.setString(2,teapwd);
        pre.setString(3,teaid);
        int count=pre.executeUpdate();
        pre.close();
        if(count>=1)
            return true;
        else
            return false;
    }
    public boolean ModifyGrades(String stuid,int grade)throws Exception
    {
        String sql="update examination set grade=? where stuid=?";
        PreparedStatement pre = connect.prepareStatement(sql);
        pre.setInt(1,grade);
        pre.setString(2,stuid);
        int count=pre.executeUpdate();
        pre.close();
        if(count>=1)
            return true;
        else
            return false;
    }