create external table with headers in netezza (postgres) - csv

Question

I am creating an external table as shown below
CREATE EXTERNAL TABLE '~\test.csv'
USING ( DELIMITER ',' Y2BASE 2000 ENCODING 'internal' REMOTESOURCE 'ODBC' ESCAPECHAR '\' )
AS SELECT * FROM TEST_TABLE;
It works fine. My question is :
Is there a way we can name the header values as column names in the test.csv file ? Is it possible in either Netezza or postgres.
I think we can do it using COPY, however I want to do it using the EXTERNAL TABLE command.
Thanks

Answer 1

In version 7.2 of Netezza you can now specify the IncludeHeader option to achieve this with external tables.
This is documented here

Answer 2

It's not pretty, and it would likely add some amount of overhead to the query, but you could do something like this:
CREATE EXTERNAL TABLE ... AS
SELECT ColumnId, OtherColumn
FROM (
SELECT FALSE as IsHeader, ColumnId::VARCHAR(512), OtherColumn::VARCHAR(512)
FROM TEST_TABLE
UNION ALL
SELECT TRUE as IsHeader, 'ColumnId', 'OtherColumn'
) x
ORDER BY IsHeader DESC

Answer 3

This is another example, along the same idea that qSlug gave...
CREATE EXTERNAL TABLE
'C:\HEADER_TEST.csv' USING
(DELIMITER '|' ESCAPECHAR '\' Y2BASE 2000 REMOTESOURCE 'ODBC') AS
--actual query goes here. Leave the 'data' field on there.
(select store_name, address1, 'data'
from yourtable
limit 10)
union
--field names go here. Leave the 'header' field on there.
select 'store_name', 'address1', 'header'
from _v_dual
order by 3 desc
You can then just delete the last column from your csv file.

Answer 4

There actually is a way to include the header in the file if you have Netezza version 7.2 or greater.
The option is 'includeheader' , but it doesn't look like the Aginity Workbench highlights 'includeheader' as though it's an option (at least in my version: 4.8).
CREATE EXTERNAL TABLE '~\test.csv'
USING
(
DELIMITER ','
Y2BASE 2000
ENCODING 'internal'
REMOTESOURCE 'ODBC'
ESCAPECHAR '\'
/****THIS IS THE OPTION ****/
INCLUDEHEADER
)
AS
SELECT *
FROM TEST_TABLE;
You'll notice that Aginity doesn't apply highlighting to the option but it will execute and write a header to the first row.