Re: Extract Column of CSV - pretend its a database.

[space_monk]

This is an alternative method to the Text::CSV techniques suggested above.

If you're familiar with databases, you can use DBD::CSV to query the CSV file as a database and select the fourth column of data.

[erix]

Why pretend? Assuming these two csv lines:

11,22,33,"ABC"
1111,3333,4444,"asdfasd asdfasdfasdf"

And assuming you have the file_fdw extension installed ( create extension file_fdw; ), you could have Pg query it via:

create server pgcsv foreign data wrapper file_fdw;

create foreign table pgcsv (
   col1 int,
   col2 int,
   col3 int,
   col4 text
) server pgcsv
options ( filename '/tmp/pm-1040691.csv', format 'csv' );

select * from pgcsv; -- or a single column, of course...

which will output:

CREATE SERVER
CREATE FOREIGN TABLE
 col1 | col2 | col3 |         col4
------+------+------+----------------------
   11 |   22 |   33 | ABC
 1111 | 3333 | 4444 | asdfasd asdfasdfasdf

Obviously not the easiest way to go about it (and on top of that, postgres is rather picky about the text's precise format). I'm just showing this because you brought up "database" ;)

[space_monk]

Well thats one idea. I presume though you'd need the psql client installed on your PC. Your answer is ingenious but not Perl :-)

[erix]

You would need much more than psql (which in fact you do not really need); you would need a running postgresql server to talk to. The talking would be done via DBI.

But again; not really recommended for the OP (or I would have made a DBI example), just a demo for fun :)