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From "Danoja Dias (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (DERBY-4555) Expand SYSCS_IMPORT_TABLE to accept CSV file with header lines
Date Sat, 28 May 2016 14:39:12 GMT

    [ https://issues.apache.org/jira/browse/DERBY-4555?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15305423#comment-15305423
] 

Danoja Dias commented on DERBY-4555:
------------------------------------

I think the type of skip should be short. 

When I study the code, I found followings.

org.apache.derby.catalog.SystemProcedures.java contains the 
SYSCS_IMPORT_TABLE function It calls ImportTable function in the org.apache.derby.impl.load.Import.java
.

Reading of csv file happens at readNextToken method in org.apache.derby.impl.load.ImportReadData.java
readNextToken reads one column's value at a time.

In org.apache.derby.impl.load.ImportReadData.java  the method ignoreFirstRow() ignores the
first row by looking for the record separator. It is done by readNextToken() method. 

I think we can use that mechenism for skipping the headerlines.





> Expand SYSCS_IMPORT_TABLE to accept CSV file with header lines
> --------------------------------------------------------------
>
>                 Key: DERBY-4555
>                 URL: https://issues.apache.org/jira/browse/DERBY-4555
>             Project: Derby
>          Issue Type: Improvement
>          Components: Miscellaneous
>            Reporter: Yair Lenga
>            Assignee: Danoja Dias
>         Attachments: petlist.csv, petlist.csv, petlist.csv, repro.java
>
>
> The SYSCS_IMPORT_TABLE (and SYSCS_IMPORT_DATA) function allow import of data from external
resources. In general, they can process CSV files that created with various tools - with one
exception: the header line.
> While there is no accepted standard, most tools will include a header line in the CSV
file with column names. This convention is supported in Excel and many other tools.
> My Request: extend the SYSCS_IMPORT_TABLe and SYSCS_IMPORT_DATA (and other related procedures)
to include an extra indicator for the number of header lines to be ignored.
> As an extra bonus it will be help is the SYSCS_IMPORT_DATA will accept column names (instead
of column indexes) in the 'COLUMNINDEXES' arguments. E.g., it should be possible to indicate
COLUMNINDEXES of '1,3,sales,5,'. This feature will make it significantly easier to handle
cases where the external input files is extended to include additional columns.



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