在上一篇文章《用Sqoop进行MySQL和DHFS系统间的数据互导》中，提到sqoop可以让RDBMS和HDFS之间互导数据，并且也支持从mysql中导入

在上一篇文章《用Sqoop进行MySQL和DHFS系统间的数据互导》中，提到sqoop可以让RDBMS和HDFS之间互导数据，并且也支持从mysql中导入到HBase，但从HBase直接导入mysql则不是直接支持，而是间接支持。要么将HBase导出到HDFS平面文件，，要么将其导出到Hive中，再导出到mysql。本篇讲从hive中导出到mysql。
从hive将数据导出到mysql

一、创建mysql表
mysql> create table award (rowkey varchar(255), productid int, matchid varchar(255), rank varchar(255), tourneyid varchar(255), userid bigint, gameid int, gold int, loginid varchar(255), nick varchar(255), plat varchar(255));
Query OK, 0 rows affected (0.01 sec)
二、尝试用hive作为外部数据库连接hbase，导入mysql
hive> CREATE EXTERNAL TABLE hive_award(key string, productid int,matchid string, rank string, tourneyid string, userid bigint,gameid int,gold int,loginid string,nick string,plat string) STORED BY 'org.apache.Hadoop.hive.hbase.HBaseStorageHandler' WITH SERDEPROPERTIES ("hbase.columns.mapping" = ":key,info:MPID,info:MatchID,info:Rank,info:TourneyID,info:UserId,info:gameID,info:gold,info:loginId,info:nickName,info:platform") TBLPROPERTIES("hbase.table.name" = "award"); hive> desc hive_award;
key string from deserializer
productid int from deserializer
matchid string from deserializer
rank string from deserializer
tourneyid string from deserializer
userid bigint from deserializer
gameid int from deserializer
gold int from deserializer
loginid string from deserializer
nick string from deserializer
plat string from deserializer
[zhouhh@Hadoop46 ~]$ hadoop fs -ls /user/hive/warehouse/
Found 3 items
drwxr-xr-x - zhouhh supergroup 0 2012-07-16 14:08 /user/hive/warehouse/hive_award
drwxr-xr-x - zhouhh supergroup 0 2012-07-16 14:30 /user/hive/warehouse/nnnon
drwxr-xr-x - zhouhh supergroup 0 2012-07-16 13:53 /user/hive/warehouse/test222 [zhouhh@Hadoop46 ~]$ sqoop export --connect jdbc:mysql://Hadoop48/toplists -m 1 --table award --export-dir /user/hive/warehouse/hive_award --input-fields-terminated-by '\0001'
12/07/19 16:13:06 INFO manager.MySQLManager: Preparing to use a MySQL streaming resultset. 12/07/19 16:13:06 INFO tool.CodeGenTool: Beginning code generation
12/07/19 16:13:06 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `award` AS t LIMIT 1
12/07/19 16:13:06 INFO orm.CompilationManager: HADOOP_HOME is /home/zhouhh/hadoop-1.0.0/libexec/..
注: /tmp/sqoop-zhouhh/compile/4366149f0b6dd311c5b622594744fbb0/award.java使用或覆盖了已过时的 API。
注: 有关详细信息, 请使用 -Xlint:deprecation 重新编译。
12/07/19 16:13:08 INFO orm.CompilationManager: Writing jar file: /tmp/sqoop-zhouhh/compile/4366149f0b6dd311c5b622594744fbb0/award.jar
12/07/19 16:13:08 INFO mapreduce.ExportJobBase: Beginning export of award
12/07/19 16:13:09 WARN mapreduce.ExportJobBase: Input path hdfs://Hadoop46:9200/user/hive/warehouse/hive_award contains no files
12/07/19 16:13:11 INFO input.FileInputFormat: Total input paths to process : 0
12/07/19 16:13:11 INFO input.FileInputFormat: Total input paths to process : 0
12/07/19 16:13:13 INFO mapred.JobClient: Running job: job_201207191159_0059
12/07/19 16:13:14 INFO mapred.JobClient: map 0% reduce 0%
12/07/19 16:13:26 INFO mapred.JobClient: Job complete: job_201207191159_0059
12/07/19 16:13:26 INFO mapred.JobClient: Counters: 4
12/07/19 16:13:26 INFO mapred.JobClient: Job Counters
12/07/19 16:13:26 INFO mapred.JobClient: SLOTS_MILLIS_MAPS=7993
12/07/19 16:13:26 INFO mapred.JobClient: Total time spent by all reduces waiting after reserving slots (ms)=0
12/07/19 16:13:26 INFO mapred.JobClient: Total time spent by all maps waiting after reserving slots (ms)=0
12/07/19 16:13:26 INFO mapred.JobClient: SLOTS_MILLIS_REDUCES=0
12/07/19 16:13:26 INFO mapreduce.ExportJobBase: Transferred 0 bytes in 16.9678 seconds (0 bytes/sec)
12/07/19 16:13:26 INFO mapreduce.ExportJobBase: Exported 0 records. 直接导外部表不成功，Input path hdfs://Hadoop46:9200/user/hive/warehouse/hive_award contains no files