将表从配置单元导出到Oracle服务器

Question

当我从Oracle db导入表到hive时很好但是当我将数据从hive导出到db时我得到了错误。我正在执行休闲查询操作。

sqoop export 
  --connect jdbc:oracle:thin:@oragmp01prscan.enterprisenet.org:1521/GMP1PROD_RLB
  --username GMPAPMETA 
  --password welcome123 
  --table activity/
  --export-dir hdfs://user/hive/warehouse/activity/

ERROR：

at org.apache.sqoop.tool.ExportTool.run(ExportTool.java:100) 
at org.apache.sqoop.Sqoop.run(Sqoop.java:143) 
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70) 
at org.apache.sqoop.Sqoop.runSqoop(Sqoop.java:179) 
at org.apache.sqoop.Sqoop.runTool(Sqoop.java:218) 
at org.apache.sqoop.Sqoop.runTool(Sqoop.java:227) 
at org.apache.sqoop.Sqoop.main(Sqoop.java:236) 
15/11/05 01:18:28 ERROR tool.ExportTool: 
Encountered IOException running export job: 
java.io.IOException: No columns to generate for ClassWriter