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I'd like to execute a query from the shell (not in the interactive psql client) and have it print the CSV or TSV representation of the output to STDOUT. How do you do that with psql or one of the PostgreSQL command-line tools?

dan
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8 Answers8

111

If you are using PostgreSQL 8.2 or newer, use this for CSV:

psql -c "COPY (<select query>) TO STDOUT WITH CSV"

and this of TSV, with proper NULLs:

psql -c "COPY (<select query>) TO STDOUT WITH NULL AS ''"

The CSV form will properly quote any fields that contain the double-quote character. See the PostgreSQL documentation of your specific version for more details and options for COPY.

Matthew Wood
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    It really does make this stuff easy, don't it? Imagine the answer from some of the "big database vendors"... First install this 64 Meg package and then run this export tool that has the most arcane syntax imaginable. Be careful not to delete your whole database while using it. :) – Scott Marlowe Jun 29 '11 at 17:18
  • Note: you can't get a header for TSVs this way, you need something like https://stackoverflow.com/a/57862424 – dfrankow Apr 17 '23 at 23:05
41

Starting from Bohemian's answer, I found these flags useful:

psql my_database -U myuser -A -F , -X -t -f /path/to/query.sql -o /path/to/output.csv
  • Unaligned output mode: -A
  • Use comma as field delimiter: -F ,
  • Do not read psqlrc: -X
  • Tuples only (no header/footer): -t
  • File containing SQL query: -f
  • Output file: -o
Jason McVetta
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8

EDITED: Using -F

Use commas via -F and use "unaligned table output mode" -A:

psql my_database -U myuser -A -F , -c "select * from mytable"
Bohemian
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    This will give problems if your separator character appears in values of the column. – Red15 Oct 23 '12 at 11:54
  • @Red15, how do you go around this problem of ` if your separator character appears in values of the column` – Jin.X Dec 04 '15 at 12:11
  • @Jin You should [ask that as a new question](http://stackoverflow.com/questions/ask) – Bohemian Dec 05 '15 at 17:30
  • @Jin.X I personally think the CSV output (which is the accepted answer) would be the easiest way. – Red15 Mar 10 '16 at 14:03
6

To specify a tsv use the delimiter '\t'

psql my_database -U myuser -F'\t' --no-align -f mysqlfile.sql -o outputfile.tsv

To specify a csv use the delimiter ','

psql my_database -U myuser -F',' --no-align -f mysqlfile.sql -o outputfile.csv
Jeff S.
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ConKat
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6

The simplest way (using psql) seems to be by using --csv flag:

psql --csv -c "SELECT * FROM sometable"
Yan Foto
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4

Also possible is the copy command which allows you to specify header, delimiters and quoting options

psql my_database -U my_user -c "copy (select a.id,b.id from my_table_a as a inner join my_table_b as b on b.id = a.id) to STDOUT"
Gavin
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3

You can specify the field separator with the -F command line parameter to psql

Szocske
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2

Export AS TSV WITH HEADER

You can include the HEADER as follows:

\COPY (SELECT * FROM tca) TO '/.../metab/tca.tsv' WITH DELIMITER E'\t' CSV HEADER;

\COPY (SELECT * FROM tca) TO '/...a/metab/tca.tsv' WITH NULL AS '' DELIMITER E'\t' CSV HEADER;

E.g. (PSQL):

[metabolism]# \COPY (SELECT * FROM tca) TO '/mnt/Vancouver/programming/data/metabolism/tca.tsv' WITH NULL AS '' DELIMITER E'\t' CSV HEADER;
COPY 22

BASH:

[victoria@victoria tsv]$ pwd
/mnt/Vancouver/programming/data/metabolism/tsv

[victoria@victoria tsv]$ head -n3 tca.tsv
uuid    src tgt rel rel_type
878b87de-0ca8-49a8-9f77-a24353e251d2    oxalosuccinic acid  oxoglutaric acid    1.1.1.42    2
7fd9cf88-495b-491b-956e-294f19097923    isocitric acid  oxoglutaric acid    1.1.1.41    2
[victoria@victoria csv]$
Victoria Stuart
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