RowSet未启用写入

Question

请帮帮我，我正在尝试更新行集中某一列的值，但我不断得到一个exception..that行集未启用写操作。我搜索了很多，但没有找到一种方法来启用行集写入。下面提到我正在使用的代码和以下异常：

Class.forName("oracle.jdbc.driver.OracleDriver");
        Connection conn = DriverManager.getConnection(
                "jdbc:oracle:thin:@localhost:1521:orcl", uname, pwd);

        String query = "select * from " + table;
        PreparedStatement preparedStatement = conn.prepareStatement(query);
        ResultSet rset = preparedStatement.executeQuery();
        OracleCachedRowSet oracleCachedRowSet = new OracleCachedRowSet();
        oracleCachedRowSet.populate(rset);
        ResultSetMetaData resultSetMetaData = oracleCachedRowSet.getMetaData();
        int numberOfColumns = resultSetMetaData.getColumnCount();

        while (oracleCachedRowSet.next()) {

            oracleCachedRowSet.updateBigDecimal(1, new BigDecimal(99));
            oracleCachedRowSet.updateRow();
            oracleCachedRowSet.acceptChanges();
            for (int i = 1; i <= numberOfColumns; i++) {

                System.out.print(oracleCachedRowSet.getString(i) + " ");

            }
        }
    }

执行上述代码时出现异常：

java.sql.SQLException: The RowSet is not write enabled
    at oracle.jdbc.rowset.OracleCachedRowSet.checkColumnIndex(OracleCachedRowSet.java:912)
    at oracle.jdbc.rowset.OracleCachedRowSet.updateObject(OracleCachedRowSet.java:5931)
    at oracle.jdbc.rowset.OracleCachedRowSet.updateBigDecimal(OracleCachedRowSet.java:6430)
    at Test.getDBConnection(Test.java:86)
    at Test.main(Test.java:37)

Answer 1

尝试设置：

oracleCachedRowSet.setReadOnly(false);

Answer 2

ResultSet的Javadoc告诉我们

默认的ResultSet对象是不可更新的，它的游标只能向前移动。

我猜，您的异常消息与该问题相关。javaDoc提供了一个如何创建可滚动和可更新结果集的示例：

Statement stmt = con.createStatement(
                                  ResultSet.TYPE_SCROLL_INSENSITIVE,
                                  ResultSet.CONCUR_UPDATABLE);
ResultSet rs = stmt.executeQuery("SELECT a, b FROM TABLE2");
// rs will be scrollable, will not show changes made by others,
// and will be updatable