PostgreSQL export result as CSV from remote server - bash

I have read all other solutions and none adapts to my needs, I do not use Java, I do not have super user rights and I do not have API's installed in my server.
I have select rights on a remote PostgreSQL server and I want to run a query in it remotely and export its results into a .csv file in my local server.
Once I manage to establish the connection to the server I first have to define the DB, then the schema and then the table, fact that makes the following lines of code not work:
\copy schema.products TO '/home/localfolder/products.csv' CSV DELIMITER ','
copy (Select * From schema.products) To '/home/localfolder/products.csv' With CSV;
I have also tried the following bash command:
psql -d DB -c "select * from schema.products;" > /home/localfolder/products.csv
and logging it with the following result:
-bash: home/localfolder/products.csv: No such file or directory
I would really appreciate if someone can show a light on this.

Have you tried this? I do not have psql right now to test it.
echo “COPY (SELECT * from schema.products) TO STDOUT with CSV HEADER” | psql -o '/home/localfolder/products.csv'
Details:
-o filename Put all output into file filename. The path must be writable by the client.
echo builtin + piping (|) pass command to psql

Aftr a while a good colleague deviced this solution which worked perfectly for my needs, hope this can help someone.
'ssh -l user [remote host] -p [port] \'psql -c "copy (select * from schema.table_name') to STDOUT csv header" -d DB\' > /home/localfolder/products.csv'
Very similar to idobr's answer.

From http://www.postgresql.org/docs/current/static/sql-copy.html:
Files named in a COPY command are read or written directly by the server, not by the client application.
So, you'll always want to use psql's \copy meta command.
The following should do the trick:
\copy (SELECT * FROM schema.products) to 'products.csv' with csv
If the above doesn't work, we'll need an error/warning message to work with.

You mentioned that the server is remote, however you are connecting to a localhost. Add the -h [server here] or set the ENV variable
export PGHOST='[server here]'
The database name should be the last argument, and not with -d.
And finally that command should have not failed, my guess is that that directory does not exist. Either create it or try writing to tmp.
I would ask you to try the following command:
psql -h [server here] -c "copy (select * from schema.products) to STDOUT csv header" DB > /tmp/products.csv

Related

Executing db2 commands from bash script giving errors?

I am a noob in running db2 commands in the unix environment, so I have been trying to connect to a db2 instance from a bash script. However I get errors here is what my script looks like:
#!/bin/bash
DB2="java com.ibm.db2.clp.db2"
$DB2 "connect to <db2 server here> user **** using ****"
I get a DSNC102I : The option "connect to <db2 server> user **** using ****" specified after the "db2" command is incorrect.
I do not know what to do from here.
Currenty I am able to run an sql script from the same bash script by using
$DB2 -tvf part3.sql where both connection details and sql queries are in the part3.sql file.
Why can't I achieve the same results by writing the sql commands themselves in the bash script.
PS:
I want this since I my bash script is required to accept any db2 instance/ schema to conduct queries as a parameter to the bash script
It looks like you're using the CLP under USS and it is interpreting the connect statement as an option flag instead of a command.
Putting the connect statement and the statements to run in a file at run time should do what you need - this script takes parameters for db2 server, username, and password so you can remove them from part3.sql:
#!/bin/bash
DB2="java com.ibm.db2.clp.db2"
echo "connect to $1 user $2 using $3;" > temp.sql
cat part3.sql >> temp.sql
$DB2 -tvf temp.sql
rm temp.sql
The connect statement is put into a temp file, then the contents of the part3.sql file are copied in and the file is run by the CLP. Finally the temp file is removed.

Unable to run psql command from within a BASH script

I have run into a problem with the psql command in my BASH script as I am trying to login to my local postgres database and submit a query. I am using the command in the following way:
psql -U postgres -d rebasoft_appauditor -c "SELECT * FROM katan_scripts"
However, I get the following error message.
psql: FATAL: Ident authentication failed for user "postgres"
This runs perfectly fine from the command line after I appended the following changes to /var/lib/pgsql/data/pg_hba.conf:
local all all trust
host all all 127.0.0.1/32 trust
Also, could this please be verified for correctness?
I find it rather strange that database authentication works fine on the command line but in a script it fails. Could anyone please help with this?
Note: I am using MAC OSX
It might possibly depend on your bash script.
Watch for the asterisk (*) not be replaced with the file names in your current directory. And possibly a semicolon or \g might help to actually send the SQL statement to the database server.

cant create file when trying to mysqldump to csv on remote server

So I have a batch server that runs a batch script. This script issues a mysqldump command for our db server.
mysqldump -h nnn.nn.nnn.nn -u username -p password --tab=/var/batchfiles/ --fields-enclosed-by='"' --fields-terminated-by="," --fields-escaped-by="\\" --lines-terminated-by="\\n" store_locations stores
When the command runs, I get an error:
Can't create/write to file '/var/mi6/batch/stores.txt' (Errcode: 2) when executing 'SELECT INTO OUTFILE'
Now I have tried also outputting to the /tmp dir as suggested at http://techtots.blogspot.com/2011/12/using-mysqldump-to-export-csv-file.html and it is still unable to write the file as it tells me it already exists, even though it doesn't.
Bottom line is, I would like to be able run a script on server A that issues a mysql command for the db server and have that output file saved to server A in csv format.
FYI, I have also tried just running mysql and redirecting output to a file. This creates a tab file but you dont have much control over the output which so it wont really work either.
mysqldump in a --tab mode is a CLI tool for SELECT INTO OUTFILE. And the latter is normally supposed to be used to create a delimited file afresh and only on the db server host.
SELECT ... INTO Syntax
The SELECT ... INTO OUTFILE statement is intended primarily to let you
very quickly dump a table to a text file on the server machine. If you
want to create the resulting file on some other host than the server
host, you normally cannot use SELECT ... INTO OUTFILE since there is
no way to write a path to the file relative to the server host's file
system.
You have at least following options:
use mysql instead of mysqldump on a remote host to create a tab delimited file instead
mysql -h<host> -u<user> -p<password> \
-e "SELECT 'column_name', 'column_name2'... \
UNION ALL SELECT column1, column2, FROM stores" > \
/path/to/your/file/file_name
you can pipe it with sed or awk and create a CSV file from a tab delimited output. See this for details
you can make a location for a file on a remote host accessible through network-mapped path on db server's file system.

How to get text that is printed into console using sybase procedure into shell script

I have a sybase procedure which prints data like: print 'Hello World'.
How can I get that text into shell script. In other words how can a shell script read from the console of the database?
You can do this a couple of different ways. If you have a script file that you are running, do the following to specify an output file:
isql -U username -P password -S servername -i Inputscript.name -o outputfile.name
It will run the script, and output the results into the file specified by the -o
To run isql 'interactively' in your script you can do the following within your shell script:
isql -U username -P password -S servername -b << ENDSQL >> outputfile.name
set nocount on \*stops displaying rows affected count*\
go
select some, data from table
go
ENDSQL
You can also use the example above to set the results of a query to a variable:
myvar = `isql -U username -P password -S servername << ENDSQL
sp_my_procedure
go
ENDSQL`
A couple of notes. If you are executing SQL statements, and are going to use the results in other processing (e.g. not just trying to print them), you will likely want to set nocount on within your SQL to prevent affected rowcount from printing, and use the -b flag in your isql connection string to prevent headers from being printed.

Shell script to execute pgsql commands in files

I am trying to automate a set of procedures that create TEMPLATE databases.
I have a set of files (file1, file2, ... fileN), each of which contains a set of pgsql commands required for creating a TEMPLATE database.
The contents of the file (createdbtemplate1.sql) looks roughly like this:
CREATE DATABASE mytemplate1 WITH ENCODING 'UTF8';
\c mytemplate1
CREATE TABLE first_table (
--- fields here ..
);
-- Add C language extension + functions
\i db_funcs.sql
I want to be able to write a shell script that will execute the commands in the file, so that I can write a script like this:
# run commands to create TEMPLATE db mytemplate1
# ./groksqlcommands.sh createdbtemplate1.sql
for dbname in foo foofoo foobar barbar
do
# Need to simply create a database based on an existing template in this script
psql CREATE DATABASE $dbname TEMPLATE mytemplate1
done
Any suggestions on how to do this? (As you may have guessed, I'm a shell scripting newbie.)
Edit
To clarify the question further, I want to know:
How to write groksqlcommands.sh (a bash script that will run a set of pgsql cmds from file)
How to create a database based on an existing template at the command line
First off, do not mix psql meta-commands and SQL commands. These are separate sets of commands. There are tricks to combine those (using the psql meta-commands \o and \\ and piping strings to psql in the shell), but that gets confusing quickly.
Make your files contain only SQL commands.
Do not include the CREATE DATABASE statement in the SQL files. Create the db separately, you have multiple files you want to execute in the same template db.
Assuming you are operating as OS user postgres and use the DB role postgres as (default) Postgres superuser, all databases are in the same DB cluster on the default port 5432 and the role postgres has password-less access due to an IDENT setting in pg_hba.conf - a default setup.
psql postgres -c "CREATE DATABASE mytemplate1 WITH ENCODING 'UTF8'
TEMPLATE template0"
I based the new template database on the default system template database template0. Basics in the manual here.
Your questions
How to (...) run a set of pgsql cmds from file
Try:
psql mytemplate1 -f file
Example script file for batch of files in a directory:
#! /bin/sh
for file in /path/to/files/*; do
psql mytemplate1 -f "$file"
done
The command option -f makes psql execute SQL commands in a file.
How to create a database based on an existing template at the command line
psql -c 'CREATE DATABASE my_db TEMPLATE mytemplate1'
The command option -c makes psql execute a single SQL command string. Can be multiple commands, terminated by ; - will be executed in one transaction and only the result of the last command returned.
Read about psql command options in the manual.
If you don't provide a database to connect to, psql will connect to the default maintenance database named "postgres". In the second answer it is irrelevant which database we connect to.
you can echo your commands to the psql input:
for dbname in foo foofoo foobar barbar
do
echo """
CREATE DATABASE $dbname TEMPLATE mytemplate1
""" | psql
done
If you're willing to go the extra mile, you'll probably have more success with sqlalchemy. It'll allow you to build scripts with python instead of bash, which is easier and has better control.
As requested in the comments: https://github.com/srathbun/sqlCmd
Store your sql scripts under a root dir
Use dev,tst,prd parametrized dbs
Use find to run all your pgsql scripts as shown here
Exit on errors
Or just git clone the whole tool from here
For that use case where you have to do it....
Here is a script I've used for importing JSON into PostgreSQL (WSL Ubuntu), which basically requires that you mix psql meta commands and SQL in the same command line. Note use of the somewhat obscure script command, which allocates a pseudo-tty:
$ more update.sh
#!/bin/bash
wget <filename>.json
echo '\set content `cat $(ls -t <redacted>.json.* | head -1)` \\ delete from <rable>; insert into <table> values(:'"'content'); refresh materialized view <view>; " | PGPASSWORD=<passwd> psql -h <host> -U <user> -d <database>
$

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