## query

有一个唯一标识符，通常这个表都有一个字段，类似于插入时间createtime

where createtime => 20150924000000000 and createtime < 20150925000000000

##sqoop参数

Incremental import arguments:

   --check-column <column>            Source column to check for incremental change

   --incremental <import-type>        Define an incremental import of type 'append' or 'lastmodified'

   --last-value <value>                   Last imported value in the incremental check column

##

bin/sqoop import \

--connect jdbc:mysql://hadoop-senior.ibeifeng.com:3306/test \

--username root \

--password 123456 \

--table my_user \

--target-dir /user/root/sqoop/imp_my_incr \

--num-mappers 1 \

--incremental append \

--check-column id \

--last-value 4  

#--incremental append       //追加方式

#--check-column        //检查的字段

#--last-value        //最后的值，不包含这个值，从这个值后面的开始导入

##

[root@hadoop-senior hadoop-2.5.0-cdh5.3.6]# bin/hdfs dfs -text /user/root/sqoop/imp_my_incr/part-m-00000

5,test,test

6,pudong,pudong

7,qiqi,qiqi

##

bin/sqoop import \

--connect jdbc:mysql://hadoop-senior.ibeifeng.com:3306/test \

--username root \

--password 123456 \

--table my_user \

--target-dir /user/root/sqoop/imp_my_incr \

--num-mappers 1 \

--delete-target-dir \

--direct