private void btnEditRoleUser_Click(object sender, EventArgs e)
        {
            OracleDataController.ConnectDB(FormLogin.connectionStr);
            string query = null;

            if (comboEditUserInfor.SelectedIndex != -1)
            {
                if (comboOldRole.Items.Count > 0)
                {
                    query = "revoke " + comboOldRole.Text + " from " + comboEditUserInfor.SelectedItem.ToString();
                    bool checkIsRevoke = OracleDataController.Revoke(query);
                    if (checkIsRevoke)
                    {
                        MessageBox.Show("Revoke role successfully!");
                    }
                }

                query = "grant " + comboEditNewRole.SelectedItem.ToString() + " to " + comboEditUserInfor.SelectedItem.ToString();
                bool checkIsGrant = OracleDataController.Grant(query);
                if (checkIsGrant)
                {
                    MessageBox.Show("Grant role successfully!");
                }
            }
        }
        private void btnEditPriInCol_Click(object sender, EventArgs e)
        {
            string grantTo = "";

            if (checkBoxPriUserInCol.Checked)
            {
                grantTo = comboEditPriInColRole.SelectedItem.ToString();
                comboEditPriInColUser.Enabled = false;
            }
            else if (checkBoxPriRoleInCol.Checked)
            {
                grantTo = comboEditPriInColUser.SelectedItem.ToString();
                comboEditPriInColRole.Enabled = false;
            }
            string queryGrantInColumn = String.Format("GRANT {0}({1}) ON {2} TO {3}"
                                                      , comboEditPriInColPri.SelectedItem.ToString(),
                                                      comboEditPriInColCol.SelectedItem.ToString(),
                                                      comboEditPrivInColTable.SelectedItem.ToString(),
                                                      grantTo);

            OracleDataController.ConnectDB(FormLogin.connectionStr);
            bool checkIfGrant = OracleDataController.Grant(queryGrantInColumn);

            if (checkIfGrant)
            {
                MessageBox.Show("Grant in column successfully!");
            }
            else
            {
                MessageBox.Show("Grant in column failed!");
                return;
            }
        }
        // Revoke privileges from user/role
        private void button1_Click(object sender, EventArgs e)
        {
            string revokeTo = "";

            comboWithGrantOption.Enabled = false;
            if (checkBoxUserPri.Checked)
            {
                revokeTo = comboEditPriviRole.SelectedItem.ToString();
                comboEditPrivUser.Enabled = false;


                if (comboEditPriviRole.SelectedIndex == -1)
                {
                    MessageBox.Show("You didn't choose the role yet!");
                    return;
                }
            }
            else if (checkBoxRolePri.Checked)
            {
                revokeTo = comboEditPrivUser.SelectedItem.ToString();
                comboEditPriviRole.Enabled = false;
                if (comboEditPrivUser.SelectedIndex == -1)
                {
                    MessageBox.Show("You didn't choose the user yet!");
                    return;
                }
            }

            if (comboPrivi.SelectedIndex == -1)
            {
                MessageBox.Show("You didn't choose the privilege yet!");
                return;
            }
            if (comboTargetObj.SelectedIndex == -1)
            {
                MessageBox.Show("You didn't choose the target object yet!");
                return;
            }


            string pri       = comboPrivi.SelectedItem.ToString();
            string targetObj = comboTargetObj.SelectedItem.ToString();

            string queryGrantPri = "revoke " + pri + " on " + targetObj + " from " + revokeTo;

            OracleDataController.ConnectDB(FormLogin.connectionStr);
            bool checkIsGrant = OracleDataController.Grant(queryGrantPri);

            if (checkIsGrant)
            {
                MessageBox.Show("Revoke privilege successfully!");
            }
        }
        private void btnEditPrivi_Click(object sender, EventArgs e)
        {
            string grantOption = "";
            string grantTo     = "";

            if (checkBoxUserPri.Checked)
            {
                grantTo = comboEditPriviRole.SelectedItem.ToString();
                comboEditPrivUser.Enabled = false;
                grantOption = "NO";

                if (comboEditPriviRole.SelectedIndex == -1)
                {
                    MessageBox.Show("You didn't choose the role yet!");
                    return;
                }
            }
            else if (checkBoxRolePri.Checked)
            {
                grantTo = comboEditPrivUser.SelectedItem.ToString();
                comboEditPriviRole.Enabled = false;
                if (comboEditPrivUser.SelectedIndex == -1)
                {
                    MessageBox.Show("You didn't choose the user yet!");
                    return;
                }
            }

            if (comboPrivi.SelectedIndex == -1)
            {
                MessageBox.Show("You didn't choose the privilege yet!");
                return;
            }
            if (comboTargetObj.SelectedIndex == -1)
            {
                MessageBox.Show("You didn't choose the target object yet!");
                return;
            }
            if (comboWithGrantOption.SelectedIndex == -1)
            {
                MessageBox.Show("You didn't choose the with grant option field yet!");
                return;
            }
            else
            {
                if (comboWithGrantOption.SelectedItem.ToString().Equals("NO"))
                {
                    grantOption = "";
                }
                else
                {
                    grantOption = " WITH GRANT OPTION";
                }
            }
            string pri       = comboPrivi.SelectedItem.ToString();
            string targetObj = comboTargetObj.SelectedItem.ToString();

            string queryGrantPri = "grant " + pri + " on " + targetObj + " to " + grantTo + grantOption;;

            OracleDataController.ConnectDB(FormLogin.connectionStr);
            bool checkIsGrant = OracleDataController.Grant(queryGrantPri);

            if (checkIsGrant)
            {
                MessageBox.Show("Grant privilege successfully!");
            }
        }