Cassandra 取回整行

发布于 2024-11-02 03:46:37 字数 938 浏览 0 评论 0原文

我正在用一个非常简单的例子来尝试 Cassandra。我在 cassandra 数据库中存储了一个列族：

[default@Hotelier] list Hotel;
Using default limit of 100
-------------------
RowKey: AZS_011
=> (column=name, value=43616d6272696120537569746573, timestamp=527682928555011)

上面的值实际上是“Cambria Suites”。当我使用以下代码从数据库检索值时：

    String key = "AZS_011";
    Connector connector = new Connector();
    Cassandra.Client client = connector.connect();

    ColumnPath cp = new ColumnPath("Hotel");
    cp.setColumn(to_bb("name"));

    ColumnOrSuperColumn col = client.get(to_bb(key), cp, CL);                                                                    
    String hotel_name = new String(col.column.value.array(), UTF8);
    System.out.println("I found: " + hotel_name);
    connector.close();

我最终得到输出：我发现：?getname坎布里亚套房酒店 ??乙？

看来通过引用 col.column.value，我已经得到了整行中的所有内容。我的问题是如何只获取没有名称和时间戳部分的值？多谢。

原文

I'm trying Cassandra with a very simple example.
I have a column family stored in the cassandra database:

[default@Hotelier] list Hotel;
Using default limit of 100
-------------------
RowKey: AZS_011
=> (column=name, value=43616d6272696120537569746573, timestamp=527682928555011)

The value above is actually "Cambria Suites". And when I use the following code to retrieve the value from the database:

    String key = "AZS_011";
    Connector connector = new Connector();
    Cassandra.Client client = connector.connect();

    ColumnPath cp = new ColumnPath("Hotel");
    cp.setColumn(to_bb("name"));

    ColumnOrSuperColumn col = client.get(to_bb(key), cp, CL);                                                                    
    String hotel_name = new String(col.column.value.array(), UTF8);
    System.out.println("I found: " + hotel_name);
    connector.close();

I end up with the output:
I found: ?getnameCambria Suites
??B?

It seems that by referring to col.column.value, I have got everything within the whole row. My question is how can I only get the value without the name and timestamp part? Thanks a lot.

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

失与倦＂ 2024-11-09 03:46:37

使用以下方式获取每一列。我让方法获取如下值：

for (ColumnOrSuperColumn c : result) {
            if (c.getColumn() != null) {
                String name = new String(c.getColumn().getName(), ENCODING);
                String value = new String(c.getColumn().getValue(), ENCODING);
                long timestamp = c.getColumn().getTimestamp();
                System.out.println("  name: '" + name + "', value: '" + value + "', timestamp: " + timestamp);
            } else {

            }
        }

Use following way to get each column. I made method get the values as below:

for (ColumnOrSuperColumn c : result) {
            if (c.getColumn() != null) {
                String name = new String(c.getColumn().getName(), ENCODING);
                String value = new String(c.getColumn().getValue(), ENCODING);
                long timestamp = c.getColumn().getTimestamp();
                System.out.println("  name: '" + name + "', value: '" + value + "', timestamp: " + timestamp);
            } else {

            }
        }

回复收藏 0 原文

~没有更多了~