I want to update a column of my database running in a VW (using Vagrant) with the host's IP.
To do this I want to use a bash script:
LOCAL_IP=$(ipconfig getifaddr en0)
SQL="vagrant ssh -c 'psql -U user -d mydatabase -h localhost -c \"update mytable set mycolumn = '$LOCAL_IP';\"'"
eval $SQL
But I get this error:
ERROR: syntax error at or near ".123"
LINE 1: update mytable set mycolumn = 123.123.123.123;
The ouput of the SQL vriable:
echo $SQL
vagrant ssh -c 'psql -U user -d mydatabase -h localhost -c "update mytable set mycolumn = '123.123.123.123';"'
When I call the psql command from echo $SQL in the vm everything is fine, but I don't have the host ip.
vagrant ssh
psql -U user -d mydatabase -h localhost -c "update mytable set mycolumn = '123.123.123.123';"
It looks like the vagrant ssh -c command would remove the single quotes around the IP. Any ideas?
UPDATE
Easiest way to reproduce my problem:
$ vagrant ssh -c 'echo "update table set column = 'test';" > bla.sql'
$ vagrant ssh
$ cat bla.sql
update table set column = test;
I found the solution here:
https://stackoverflow.com/a/20498919/5902456
It looks now like this:
SQL="vagrant ssh -c 'psql -U user -d mydatabase -h localhost -c \"update mytable set mycolumn = '\''$LOCAL_IP'\'';\"'"
Related
I want to export a random entry of my database into a file with the command
SELECT * FROM my_table ORDER BY RANDOM() LIMIT 1 \g /path/file;
This query works if I enter it in my db terminal, but I want to us this query with a bash script but then I get the error: syntax error at or near "\g"
My bash script looks like this:
PGPASSWORD=*** psql -U user -d db_name -h localhost -p port -t -c "SELECT * FROM my_table ORDER BY RANDOM() LIMIT 1 \g /path/file"
Bash is interpreting the string and trying to interpolate it. Probably, escaping the backslash will solve your problem.
PGPASSWORD=*** psql -U user -d db_name -h localhost -p port -t -c "SELECT * FROM my_table ORDER BY RANDOM() LIMIT 1 \\g /path/file"
A SQL statement terminated by \g is not supported by the -c command switch. Per documentation of -c:
-c command
...
command must be either a command string that is completely parsable by the server (i.e., it contains no psql-specific features), or a single backslash command. Thus you cannot mix SQL
and psql meta-commands with this option
To redirect the results to a file, there are several options:
shell redirection: psql [other options] -Atc 'SELECT...' >/path/to/data.txt
-A is to switch to unaligned mode (no space fillers to align columns).
put the SQL part in a heredoc text instead of the command line:
psql [options] <<EOF
SELECT ... \g /path/to/file
EOF
This form has the advantage that multiline statements or multiple statements are supported directly.
\copy of the query. Be aware that COPY to a FILE is different: it creates the file on the server with the permissions of postgres and requires being a database superuser. COPY TO STDOUT works too but is not better than SELECT concerning the redirection.
I found a solution for my script, and now it works.
#!/bin/bash
RANDOM_NUMBER=0
while true
do
for i in `seq 1`
do
RANDOM_NUMBER=$(($RANDOM % 100000))
echo $RANDOM_NUMBER
PGPASSWORD=*** psql -U user_name -d db_name -h localhost -p PORT -c
"INSERT INTO numbers (number) VALUES ('$RANDOM_NUMBER');"
done
sleep 10
for i in `seq 1`
do
PGPASSWORD=*** psql -U user_name -d db_name -h localhost -p PORT -c
"DELETE FROM numbers WHERE id = (SELECT id FROM numbers ORDER BY RANDOM() LIMIT 1);"
done
done
I have this code $(echo "psql -U postgres -d mydb -c "SELECT * FROM table_name;" " | ssh $REMOTE_IP)
I need to run that query in the remote host, but i can't apply the query part in the echo
Any help?
Your syntax is incorrect and you don't need to use pipe. Try this:
ssh "$REMOTE_IP" 'psql -U postgres -d mydb -c "SELECT * FROM table_name;"'
The code i tried in bash executed by root.
#!/bin/bash
su - postgres <<EOF1
F="$(psql -d postgres --tuples-only -P format=unaligned -c "SELECT datname FROM pg_database JOIN pg_authid ON pg_database.datdba = pg_authid.oid WHERE rolname = 'username'")"
EOF1
echo $F
It gives output as
ERROR: permission denied for relation pg_authid
But when i try
su - postgres <<EOF1
psql -d postgres --tuples-only -P format=unaligned -c "SELECT datname FROM pg_database JOIN pg_authid ON pg_database.datdba = pg_authid.oid WHERE rolname = 'username'"
EOF1
This prints all db of that username. Why so?
I need to store the ouput to a bash variable for further processing.
Is there any mistake or anyother way to try this out..
Thanks.
The inner $(...) expression gets executed before the su part, so it will not be run as postgres but as the current user. This is probably better written as:
command="psql -d postgres --tuples-only -P format=unaligned -c \"SELECT datname FROM pg_database JOIN pg_authid ON pg_database.datdba = pg_authid.oid WHERE rolname = 'username'\""
F=$( su - postgres -c "$command" )
You could put it all together, however:
F=$( su - postgres -c "psql -d postgres --tuples-only -P format=unaligned -c \"SELECT datname FROM pg_database JOIN pg_authid ON pg_database.datdba = pg_authid.oid WHERE rolname = 'username'\"" )
I should also note that the first example that failed for you probably would not set F to anything you could read outside of the su. However, Ubuntu and I presume other modern Linux systems do not allow you to use su in this way. You should use, e.g., sudo -l -u postrges and configure /etc/sudoers appropriately for people to have permission to run psql or whatnot as the postgres user.
What should I do for making it work?
#!/bin/bash
TABLENAMES="user_stats"
ssh -t railsapps#xxx.xxx.xxx.xx -p xxx bash -c "'
for TABLENAME in $TABLENAMES
do
psql -d mydb -P format=unaligned -P tuples_only -P fieldsep=\, -c "SELECT * FROM $TABLENAME" > /tmp/$TABLENAME
done
'"
General problem: how to periodically dump the database tables to a local machine from a psql database in a single bash script run on Mac OS X?
Firstly, you should test your SQL and bash scripts remotely (do SSH interactively).
I think your problem is caused by a bad mix of quote / double-quote. I think the star (*) and $TABLENAME are expensed before the SSH call, so too early. Try to put a backslash before the $ sign.
You should use the verbose or the debug option, to help to understand what is really executed:
ssh -t railsapps#xxx.xxx.xxx.xx -p xxx bash -vxc "'
for TABLENAME in \$TABLENAMES; do
psql -d mydb -P format=unaligned -P tuples_only -P fieldsep=\, -c "SELECT \* FROM \$TABLENAME" > /tmp/\$TABLENAME
done
'"
How to atore a scalar postgresql-value on a bash-variable like in script below?
dbname="testlauf"
username="postgres"
vartest='psql -c -d $dbname -U $username -h localhost -p 5432 "SELECT gid FROM testtable WHERE aid='1';"'
echo "$vartest"
I tried several different writings, but nothing seems to work. Thanks in advance.
Put the -c option just before its argument - the query. Mind also using the additional -t option to get just the tuple value. And of course, use the backticks (`) operator.
Using the -X option is also recommended, as sometimes a .psqlrc file might add some redundant output, as well as the -A option, which disables column aligning (whitespaces).
In order to skip NOTICE or other additional messages, include the -q flag.
vartest=`psql -d $db -U $user -AXqtc "SELECT gid FROM testtable WHERE aid='1'"`
Using -t option or --tuples-only will give you the rows only, so it will easier to store them in array variable (if the result from query more than one)
vartest =(`psql -t -d $dbname -U $username -c "SELECT gid FROM testtable WHERE aid='1';"`)
echo $vartest
example:
query result
ubuntu#ratnakri:~$ psql -h localhost -p 5432 -t -U postgres -d postgres -c "select slot_name from pg_replication_slots"
barman
barman2
make it into array variable
ubuntu#ratnakri:~$ RESULT=(`psql -h localhost -p 5432 -t -U postgres -d postgres -c "select slot_name from pg_replication_slots"`)
ubuntu#ratnakri:~$ echo ${RESULT[0]}
barman
ubuntu#ratnakri:~$ echo ${RESULT[1]}
barman2