[jira] [Created] (KYLIN-3934) sqoop import param '--null-string' result in null value become blank string in hive table

["wanghao (JIRA)" <ji...@apache.org>]

wanghao created KYLIN-3934:
------------------------------

             Summary: sqoop import param '--null-string' result in null value become blank string in hive table
                 Key: KYLIN-3934
                 URL: https://issues.apache.org/jira/browse/KYLIN-3934
             Project: Kylin
          Issue Type: Bug
          Components: Others
    Affects Versions: v2.6.0
            Reporter: wanghao


when column value from jdbc is null, sqoop will write it into hive table with blank string.

eg 

jdbc:

A | B

1 | 1

2 | 2

a | null

 

hive table:

A | B

1 | 1

2 | 2

a |

because of this, when I use count(distinct B), it return 3, not 2, and it can lead to other problems

 

 
{code:java}
String cmd = String.format(Locale.ROOT,
"%s/bin/sqoop import" + generateSqoopConfigArgString()
+ "--connect \"%s\" --driver %s --username %s --password %s --query \"%s AND \\$CONDITIONS\" "
+ "--target-dir %s/%s --split-by %s --boundary-query \"%s\" --null-string '' "
+ "--fields-terminated-by '%s' --num-mappers %d",
sqoopHome, connectionUrl, driverClass, jdbcUser, jdbcPass, selectSql, jobWorkingDir, hiveTable,
splitColumn, bquery, filedDelimiter, mapperNum);
{code}
the param '–null=string' should be '\\N' instead of blank string ''.

I resolved this problem by replace the param. But it needs be configured in kylin.properties

 

 

 



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