I am new in bash and psql, I want to write a bash code that login a server the connect to psql database do a select query and then return the output. the set up I have as follow.
server named dbs, it has psql install and running. database name = dname, user= tester passwrod = 1234
in the database there is table called node_info it has 3 colons ip, mac, connection_time.
I want to run following query
select ip, connection_time from node_info where ip=10.10.10.2;
Any tips how to write a shell script to do this remotely?
If you have properly set your "pg_hba.conf" configuration file to achieve remote connections, you may try the following:
psql -U tester -h remoteip -p remoteport -d dname -W -c "select ip, connection_time from node_info where ip='10.10.10.2'"
Related
Consider the following code:
sqls='/mnt/c/alias/Binn/SQLCMD.EXE -b -S HostName -U Username -P MyPW# -d dbName'
which is the prefix of the command to connect to the SQL Server DB dbName with username Username on the HostName
`$sqls -Q "select 1;"`
executes select 1 statement on it and it works as expected.
$($sqls -Q "select 1;")
fails. Why? Is it because of the '#' in the password? How should I change the sqls line above so it works with $(...) expression?
Storing a command in a string is prone to failure. We could work out why it's not working, but the better thing to do would be to use a function:
sql() {
/mnt/c/alias/Binn/SQLCMD.EXE -b -S HostName -U Username -P 'MyPW#' -d dbName -Q "$1"
}
This allows the password to be quoted, removing the possibility that it can break the command.
Use it like sql 'select 1'. Save the result using a standard command substitution:
foo=$(sql 'select 1')
Also bear in mind that you can use a config file (possibly $HOME/.my.cnf, but it looks like you're on Windows so not sure) to store default user, pass and database, enabling you to run queries without passing all those options every time.
I am trying to fetch some data using psql command. If I run the command directly in the console its working fine. The same command if I try to run from shell script, it says unable to connect to psql server. I have checked the listen_address variable in postgresql.conf, as I expected it was set to some name instead of * or localhost.
This server is running under cluster environment, so its using virtual ip in listen_address. The pg_hba.conf allowing local (IPv4 and IPv6) with trust authentication.
It makes sense to me so far. But, I'm confused why it isn't allowing through shell script on same server?
Edit 1:
myuser # psql -d mydb -U postgres -c "select 1"
?column?
----------
1
(1 row)
myuser # cat myscript.sh
psql -d mydb -U postgres -c "select 1"
myuser # sh myscript.sh
psql: could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/run/postgresql/.s.PGSQL.5432"?
I'm in a windows environemnt and kicked off psql. I've tried running -a -f filename.sql and psql filename.sql. This what I keep getting:
scala_db-# psql C:/Users/user/Desktop/emps.sql;
ERROR: syntax error at or near "psql"
LINE 1: psql C:/Users/user/Desktop/...
From the command line:
scala_db-# psql C:/Users/user/Desktop/emps.sql;
Looks like you already enter into the psql command line.
If so, you can use meta command \i to execute the SQL file.
e.g.
mydb=# \! echo "select 1" > c:/pgccc/tmp.sql
mydb=# \i c:/pgccc/tmp.sql
?column?
----------
1
(1 row)
If you hasn't logged into psql command line, you can use one single psql command line to execute the sql file.
e.g.
psql mydb -f c:/pgccc/tmp.sql
?column?
----------
1
(1 row)
Here the "mydb" is the target database. If not specified, you will connect to the default database.
When you run windows cmd
psql -U username dbname -f filename.sql
username is your user name,
dbname is your database name,
filename.sql is your file
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
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>
$