[
https://issues.apache.org/jira/browse/SQOOP-1295?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13940850#comment-13940850
]
Ajay Chitre commented on SQOOP-1295:
------------------------------------
Hello,
Virendra (Singh) & I ran into this issue while working on a project at Cisco.
We are importing some tables from Teradata that have UPI (unique primary key)
which is made up of more than one column. When we tried to use:
--merge-key ‘column1, column2’
We got an error saying: “Cannot join values on null key. Did you specify a key
column that exists?”
To get around this, we added a method (getKeyObject) in MergeMapperBase given
below that takes in a comma separated list. This is being called in
‘processRecord’ method as follows:
String keyObj = getKeyObject(fieldMap, keyColName, "\u0001");
We’ve attached two files (DlMergeMapperBase.java & DlMergeMapperBase_Test) for
your review. If the ‘Dev’ team thinks this is useful we will submit a patch.
Thanks.
- Ajay Chitre
[email protected]
Virendra Singh
[email protected]
public String getKeyObject(Map<String, Object> fieldMap, String mergeKey,
String fieldSeparator)
throws IOException {
assert (fieldMap != null);
assert (mergeKey != null);
assert (fieldSeparator != null);
String key = "";
String columns[] = mergeKey.split(",");
for (int i = 0; i < columns.length; i++) {
if (i != 0) {
key += fieldSeparator;
}
Object value = fieldMap.get(columns[i].trim());
if (value == null) {
throw new IOException("Cannot join values on null key. "
+ "Did you specify a key column that exists?");
}
key += value.toString();
}
return key;
}
> Sqoop Merge supports only one column merge key. Merge fails if source table
> as composite key
> --------------------------------------------------------------------------------------------
>
> Key: SQOOP-1295
> URL: https://issues.apache.org/jira/browse/SQOOP-1295
> Project: Sqoop
> Issue Type: Bug
> Components: tools
> Affects Versions: 1.4.4
> Environment: Linux
> Reporter: Virendra Singh
> Fix For: 1.4.5
>
> Attachments: DlMergeMapperBase.java, DlMergeMapperBase_Test.java
>
>
--
This message was sent by Atlassian JIRA
(v6.2#6252)
