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^_^ 大家好：

如何在 Thrift 的 C++ 中使用方法“scannerOpenWithScan()”和 filterString。hbase 版本是 hbase-0.92.1。

我想根据列的值选择行，所以我将scannerOpenWithScan()添加到“examples/thrift/DemoClient.cpp”中：

/**
* open a scanner with scan (filter string)
*/
320     TScan tscan;
321     std::string filterStr;
322     filterStr = "SingleColumnValueFilter (<=, '25', 'entry', 'num', true, false)";
323     tscan.__set_filterString(filterStr);       
324         
325     std::cout << "Starting scanner with scan..." << std::endl;
326     scanner = client.scannerOpenWithScan(t, tscan); 
327     std::cout << "The scanner id is " << scanner << std::endl;
328     try { ...... }

但是没有返回扫描仪ID，错误是：

Starting scanner with scan...
ERROR: No more data to read.

thrift.log 错误是：

796 java.lang.IllegalArgumentException: Incorrect filter string SingleColumnValueFilter(<=, '25', 'entry', 'num', true, false)
797         at org.apache.hadoop.hbase.filter.ParseFilter.parseSimpleFilterExpression(ParseFilter.java:250)
798         at org.apache.hadoop.hbase.filter.ParseFilter.parseFilterString(ParseFilter.java:168)
799         at org.apache.hadoop.hbase.thrift.ThriftServer$HBaseHandler.scannerOpenWithScan(ThriftServer.java:766)

thrift.out 是：

java.lang.reflect.InvocationTargetException
  6         at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  7         at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
  8         at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  9         at java.lang.reflect.Method.invoke(Method.java:616)
 10         at org.apache.hadoop.hbase.filter.ParseFilter.parseSimpleFilterExpression(ParseFilter.java:240)
 11         at org.apache.hadoop.hbase.filter.ParseFilter.parseFilterString(ParseFilter.java:168)
 12         at org.apache.hadoop.hbase.thrift.ThriftServer$HBaseHandler.scannerOpenWithScan(ThriftServer.java:766)
 13         at org.apache.hadoop.hbase.thrift.generated.Hbase$Processor$scannerOpenWithScan.getResult(Hbase.java:3821)

我对此一无所知。有谁知道如何使用具有过滤功能的 C++ 来访问 HBase？

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1 回答 1

6

现在我知道答案了：过滤字符串不正确，正确的是：

filterStr = "SingleColumnValueFilter('entry', 'num', =, 'substring:25', true, false)";

正确的语法是：

SingleColumnValueFilter('<family>', '<qualifier>', <compare operator>, '<comparator>', <filterIfColumnMissing_boolean>, <latest_version_boolean>)

https://issues.apache.org/jira/browse/HBASE-5946上的详细信息

于 2012-07-10T01:46:15.407 回答