Attempted to generate class with no column

14/12/23 04:31:03 ERROR tool.ImportTool: Imported Failed: Attempted to generate class with no column

1、导致该问题的原因是
sqoop import --connect jdbc:oracle:thin:@192.168.1.136:1521/jist --username UAP --password uap --table YKBZ_DETAIL --hive-import

中将用户名小写，
解决办法：将小写uap改为大写UAP

Sqoop 把数据从Oracle中迁移到Hive中时发生错误：

[hadoop@Master ~]$ sqoop import --connect jdbc:oracle:thin:@192.168.6.77:1521:orcl --username micmiu -P --table T_DEMO --warehouse-dir /user/sqoop --hive-import --create-hive-table
Warning: /usr/lib/hcatalog does not exist! HCatalog jobs will fail.
Please set $HCAT_HOME to the root of your HCatalog installation.
Enter password:
14/04/11 11:30:18 INFO tool.BaseSqoopTool: Using Hive-specific delimiters for output. You can override
14/04/11 11:30:18 INFO tool.BaseSqoopTool: delimiters with --fields-terminated-by, etc.
14/04/11 11:30:18 WARN tool.BaseSqoopTool: It seems that you've specified at least one of following:
14/04/11 11:30:18 WARN tool.BaseSqoopTool: 	--hive-home
14/04/11 11:30:18 WARN tool.BaseSqoopTool: 	--hive-overwrite
14/04/11 11:30:18 WARN tool.BaseSqoopTool: 	--create-hive-table
14/04/11 11:30:18 WARN tool.BaseSqoopTool: 	--hive-table
14/04/11 11:30:18 WARN tool.BaseSqoopTool: 	--hive-partition-key
14/04/11 11:30:18 WARN tool.BaseSqoopTool: 	--hive-partition-value
14/04/11 11:30:18 WARN tool.BaseSqoopTool: 	--map-column-hive
14/04/11 11:30:18 WARN tool.BaseSqoopTool: Without specifying parameter --hive-import. Please note that
14/04/11 11:30:18 WARN tool.BaseSqoopTool: those arguments will not be used in this session. Either
14/04/11 11:30:18 WARN tool.BaseSqoopTool: specify --hive-import to apply them correctly or remove them
14/04/11 11:30:18 WARN tool.BaseSqoopTool: from command line to remove this warning.
14/04/11 11:30:18 INFO tool.BaseSqoopTool: Please note that --hive-home, --hive-partition-key,
14/04/11 11:30:18 INFO tool.BaseSqoopTool: 	 hive-partition-value and --map-column-hive options are
14/04/11 11:30:18 INFO tool.BaseSqoopTool: 	 are also valid for HCatalog imports and exports
14/04/11 11:30:18 INFO manager.SqlManager: Using default fetchSize of 1000
14/04/11 11:30:18 INFO tool.CodeGenTool: Beginning code generation
14/04/11 11:30:19 INFO manager.OracleManager: Time zone has been set to GMT
14/04/11 11:30:19 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM T_DEMO t WHERE 1=0
14/04/11 11:30:19 ERROR tool.ImportTool: Imported Failed: Attempted to generate class with no columns!

这个原因是因为：

-username

micmiu 用户名这个参数，
需要把用户名大写：

-username

MICMIU ，再执行就ok了。