[英]How to get all the rows given a part of the row key in Hbase
I have the following table structure in Hbase: 我在Hbase中具有以下表结构:
Row column+cell
Mary_Ann_05/10/2013 column=cf:verified, timestamp=234454454,value=2,2013-02-12
Mary_Ann_06/10/2013 column=cf:verified, timestamp=2345454454,value=3,2013-02-12
Mary_Ann_07/10/2013 column=cf:verified, timestamp=2345454522454,value=4,2013-02-12
Mary_Ann_08/10/2013 column=cf:verified, timestamp=23433333454,value=1,2013-12-12
I want to retrieve all the records that start with Mary_Ann
using java. 我想使用Java检索以
Mary_Ann
开头的所有记录。 How do I do that? 我怎么做?
You could achieve that using PrefixFilter
. 您可以使用
PrefixFilter
来实现。 Given a prefix, specified when you instantiate the filter instance, all rows that match this prefix are returned to the client. 给定一个实例化过滤器实例时指定的前缀,与此前缀匹配的所有行都将返回给客户端。 The constructor is :
public PrefixFilter(byte[] prefix)
构造函数为:
public PrefixFilter(byte[] prefix)
Usage : 用法:
Filter filter = new PrefixFilter(Bytes.toBytes("Mary_Ann"));
Scan scan = new Scan();
scan.setFilter(filter);
ResultScanner scanner = table.getScanner(scan);
for (Result result : scanner) {
for (KeyValue kv : result.raw()) {
System.out.println("KV: " + kv + ", Value: " +
Bytes.toString(kv.getValue()));
}
}
scanner.close();
HTH 高温超导
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