I want to copy table from postgis database to the PC hard drive (format can be .txt .xls .csv or whatever).
How it can be done?
Use the SQL COPY command to write to the file system of the database server.
COPY tbl TO '/path/to/file/tbl.sql';
There are lots of options to adapt the output format.
Have a look at the \copy meta-command of psql if you need to copy from a remote server to the local disk.
Related
I'm familiarizing myself with the standalone version of Datagrip and having a bit of trouble understanding the different approaches to composing SQL via console, external files, scratch files, etc.
I'm managing, referencing the documentation, and am happy to figure things out as such.
However, I'm trying to ingest CSV data into tables via batch files using the Postgres \copy command. Datagrip will execute this command without error but no data is being populated.
This is my syntax, composed and ran in the console view:
\copy tablename from 'C:\Users\username\data_file.txt' WITH DELIMITER E'\t' csv;
Note that the data is tab-separated and stored in a .txt file.
I'm able to use the import functions of Datagrip (via context menu) just fine but I'd like to understand how to issue commands to do similarly.
\copy is a command of the command-line PostgreSQL client psql.
I doubt that Datagrip invokes psql, so it won't be able to use \copy or any other “backslash command”.
You probably have to use Datagrip's import facilities. Or you start using psql.
Ok, but what about the SQL COPY command https://www.postgresql.org/docs/12/sql-copy.html ?
How can I run something like that with datagrip ?
BEGIN;
CREATE TEMPORARY TABLE temp_json(values text) ON COMMIT DROP;
COPY temp_json FROM 'MY_FILE.JSON';
SELECT values->>'aJsonField' as f
FROM (select values::json AS values FROM temp_json) AS a;
COMMIT;
I try to replace 'MY_FILE.JSON' with full path, parameter (?), I put it in sql directory etc.
The data grip answer is :
[2021-05-05 10:30:45] [58P01] ERROR: could not open file '...' for reading : No such file or directory
EDIT :
I know why. RTFM! -_-
COPY with a file name instructs the PostgreSQL server to directly read from or write to a file. The file must be accessible by the PostgreSQL user (the user ID the server runs as) and the name must be specified from the viewpoint of the server.
Sorry.....
I am having multiple of csv.gz files in local computer which I want to upload into postgres table without unzipping the file. I had refer to this questions (Loading zipped CSV(filename.csv.gz) file into PostgreSQL table) and used this query
\COPY TABLE FROM PROGRAM 'gzip -dc my_file.csv.gz' DELIMITER ',' CSV HEADER NULL;
when I run it on sql shell it shown this notification "gzip is not recognized as an internal or external command". Could anyone suggest me how to do it correctly
I tried to make a variable in SQL statement in Postgresql, but it did not work.
There are many csv files stored under the path. I want to set path in Postgresql that can tell copy command where can find csv files.
SQL statement sample:
\set outpath '/home/clients/ats-dev/'
\COPY licenses (_id, name,number_seats ) FROM :outpath + 'licenses.csv' CSV HEADER DELIMITER ',';
\COPY uploaded_files (_id, added_date ) FROM :outpath + 'files.csv' CSV HEADER DELIMITER ',';
It did not work. I got error: no such files. The two files licneses.csv and files.csv are stored under /home/cilents/ats-dev on Ubuntu. I found some sultion that use "\set file 'license.csv'". It did not work for me becacuse I have many csv files. also I tried to use "from : outpath || 'licenses.csv'". it did not work ether. Appreciate for any helps.
Using 9.3.
It looks like psql does not support :variable substitution withinpsql backslash commands.
test=> \set somevar fred
test=> \copy z from :somevar
:somevar: No such file or directory
so you will need to do this via an external tool like the unix shell. e.g.
for f in *.sql; do
psql -c "\\copy $(basename $f) FROM '$f'"
done
You can try COPY command
\set outpath '\'/home/clients/ats-dev/'
COPY licenses (_id, name,number_seats ) FROM :outpath/licenses.csv' WITH CSV HEADER DELIMITER ',';
COPY uploaded_files (_id, added_date ) FROM :outpath/files.csv' WITH CSV HEADER DELIMITER ',';
Note: Files named in a COPY command are read or written directly by the server, not by the client application. Therefore, they must reside on or be accessible to the database server machine, not the client. They must be accessible to and readable or writable by the PostgreSQL user (the user ID the server runs as), not the client. Similarly, the command specified with PROGRAM is executed directly by the server, not by the client application, must be executable by the PostgreSQL user. COPY naming a file or command is only allowed to database superusers, since it allows reading or writing any file that the server has privileges to access.
Documentation: Postgresql 9.3 COPY
It may have been true when this was originally asked, that psql backslash commands didn't support variable interpolation, but in my PostgreSQL 14 instance that's no longer the case. However, the psql manpage is clear that \copy specifically does not support variable interpolation.
we can use
copy (select * from mytbl) to 'D:/products.csv' with csv header
to import data in mytbl to local disk D
so is it possible to use the same method to upload the file directly into a FTP-Server ?
i tried like this
copy (select * from mytbl) to 'ftp://usrname:mypasswrd#ftp.drivehq.com/masters/3/product/products.csv' with csv header
but got this error
ERROR: relative path not allowed for COPY to file
SQL state: 42602
using PostgreSQL 9.2
PostgreSQL does not support any source/destination for COPY other than a file or stdin/stdout.
What you can do is COPY to stdout and pipe that to a program that writes the data to the ftp dir. psql's \copy is useful for this:
psql -c "\copy mytable to stdout with (format csv, header)" | ncftpput -c my.ftp.host /path/on/host
You can use any tool that accepts the input data on a pipe to write to the remote ftp file; ncftpput is just one option.
A future PostgreSQL version may add support for invoking COPY with a pipe, e.g. COPY ... TO '|/some/command', but there are serious security concerns with running programs under the PostgreSQL user that would make this a superuser-only operation and of questionable safety even then. It's much safer to run the program client-side, and psql is ideal for that.
I would like to important a file into my Postgresql system(specificly RedShift). I have found a arguement for copy that allows importing a gzip file. But the provider for the data I am trying to include in my system only produces the data in a .zip. Any built in postgres commands for opening a .zip?
From within Postgres:
COPY table_name FROM PROGRAM 'unzip -p input.csv.zip' DELIMITER ',';
From the man page for unzip -p:
-p extract files to pipe (stdout). Nothing but the file data is sent to stdout, and the files are always extracted in binary
format, just as they are stored (no conversions).
Can you just do something like
unzip -c myfile.zip | gzip myfile.gz
Easy enough to automate if you have enough files.
This might only work when loading redshift from S3, but you can actually just include a "gzip" flag when copying data to redshift tables, as described here:
This is the format that works for me if my s3 bucket contains a gzipped .csv.
copy <table> from 's3://mybucket/<foldername> '<aws-auth-args>' delimiter ',' gzip;
unzip -c /path/to/.zip | psql -U user
The 'user' must be have super user right else you will get a
ERROR: must be superuser to COPY to or from a file
To learn more about this see
https://www.postgresql.org/docs/8.0/static/backup.html
Basically this command is used in handling large databases