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.
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 have my database hosted on heroku, and I want to download specific parts of the database (e.g. all the rows with id > x from table 1, all the rows with name = x from table 2, etc.) in a single file.
From some research and asking a question here it seems that some kind of modified pg_dump would solve my problem. However, I won't be able to use pg_dump because I won't have access to the command line (basically I want to be able to click a button in my web app and it will generate + download the database file).
So my new strategy is to use the postgres copy command. I'll go through the various tables in my server database, run COPY (Select * FROM ... WHERE ...) TO filename , where filename is just a temporary file that I will download when complete.
The issue is that this filename file will just have the rows, so I can't just turn around and import it into pgadmin. Assuming I have an 'empty' database set up (the schema, indices, and stuff are all already set up), is there a way I can format my filename file so that it can be easily imported into a postgres db?
Building on my comment about to/from stdout/stdin, and answering the actual question about including multiple tables in one file; you can construct the output file to interleave copy ... from stdin with actual data and load it via psql. For example, psql will support input files that look like this:
copy my_table (col1, col2, col3) from stdin;
foo bar baz
fizz buzz bizz
\.
(Note the trailing \. and that the separators should be tabs; you could also specify the delimiter option in the copy command).
psql will treat everything between the ';' and '.' as stdin. This essentially emulates what pg_dump does when you export table data and no schema (e.g., pg_dump -a -t my_table).
The resulting load could be as simple as psql mydb < output.dump.
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 use the COPY function in PostgreSQL to import a CSV file into a PostgreSQL database.
Where it says the filename in the documentation, does the CSV file have to be stored in a specific location or can it be stored in any location.
For example, copy data_table from '/tmp/outputdata.csv' WITH DELIMITER AS ',' CSV QUOTE AS '"';. Where it says tmp, does that mean the tmp folder in the C: drive. Can it be change to another folder name?
It looks like you are confused by Linux vs. Windows file-path notation. What you have there is a Linux path anchored to root. Windows uses drive letters, which you can specify just as well when you are running on Windows.
If you use Windows notation, take care that you have to escape backslashes if you are not using standard_conforming_strings = on - which is the default in Postgres 9.1 or later, but not in older versions. Like:
COPY data_table from E'C:\\tmp\\outputdata.csv' WITH ...
With standard_conforming_strings = on you can simply write:
COPY data_table from 'C:\tmp\outputdata.csv' WITH ...
Note that a PostgreSQL Windows server also understands default path notation with slashes instead of backslashes.
For SQL COPY FROM / TO you can use any path that the owner of server process (postgres by default) has permission to read / write.
For the \copy meta command of the psql client the permissions of current local user apply.
Yes, of course you can specify whatever location where you have read access. There's no problem changing the path of the file.
Keep attention only on the fact that on windows you have to escape the backslash in this way :
copy data_table from 'c:\\Temp\\outputdata.csv' WITH DELIMITER AS ',' CSV QUOTE AS '"';
I need to export the resulting data from a query in PostgreSQL to Excel/CSV.
I use PostgreSQL 8.2.11.
SQL error:
ERROR: relative path not allowed for COPY to file
In statement:
COPY (select distinct(m_price) from m_product)TO '"c:\auto_new.txt"';
Example with Unix-style file name:
COPY (SELECT * FROM tbl) TO '/var/lib/postgres/myfile1.csv' format csv;
Read the manual about COPY (link to version 8.2).
You have to use an absolute path for the target file. Be sure to double quote file names with spaces. Example for MS Windows:
COPY (SELECT * FROM tbl)
TO E'"C:\\Documents and Settings\\Tech\Desktop\\myfile1.csv"' format csv;
In PostgreSQL 8.2, with standard_conforming_strings = off per default, you need to double backslashes, because \ is a special character and interpreted by PostgreSQL. Works in any version. It's all in the fine manual:
filename
The absolute path name of the input or output file. Windows users might need to use an E'' string and double backslashes used as path separators.
Or the modern syntax with standard_conforming_strings = on (default since Postgres 9.1):
COPY tbl -- short for (SELECT * FROM tbl)
TO '"C:\Documents and Settings\Tech\Desktop\myfile1.csv"' (format csv);
Or you can also use forward slashes for filenames under Windows.
An alternative is to use the meta-command \copy of the default terminal client psql.
You can also use a GUI like pgadmin and copy / paste from the result grid to Excel for small queries.
Closely related answer:
Copy results from a PostgreSQL view in one DB to a table in another
Similar solution for MySQL:
Exporting MYSQL data into Excel/CSV via php
In PostgreSQL 9.4 to create to file CSV with the header in Ubuntu:
COPY (SELECT * FROM tbl) TO '/home/user/Desktop/result_sql.csv' WITH CSV HEADER;
Note: The folder must be writable.
This worked for me:
COPY (SELECT * FROM table)
TO E'C:\\Program Files (x86)\\PostgreSQL\\8.4\\data\\try.csv';
In my case the problem was with the writing permission to a special folder (though I work as administrator), after changing the path to the original data folder under PostgreSQL I had success.
Several GUI tools like Squirrel, SQL Workbench/J, AnySQL, ExecuteQuery can export to Excel files.
Most of those tools are listed in the PostgreSQL wiki:
http://wiki.postgresql.org/wiki/Community_Guide_to_PostgreSQL_GUI_Tools
If you have error like "ERROR: could not open server file "/file": Permission denied" you can fix it that:
Ran through the same problem, and this is the solution I found:
Create a new folder (for instance, tmp) under /home
$ cd /home
make postgres the owner of that folder
$ chown -R postgres:postgres tmp
copy in tmp the files you want to write into the database, and make sure they also are owned by postgres.
That's it. You should be in business after that.
The correct script for postgres (Ubuntu) is:
COPY (SELECT * FROM tbl) TO '/var/lib/postgres/myfile1.csv';