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
Related
I have a script which backups multiple tables in a single line as follow:
/usr/local/pgsql/bin/pg_dump --quote-all-identifiers --username=postgres -p 5432 -t schema.table1 -t schema.table2 -t schema.table3 -t schema.table4 -h localhost mydb | gzip -1 > file.dmp.gz
I've created a new sh script to be able to re-utilize the command as follow:
backup_table.sh
$TABLE=$1
$DESTINATION=$2
/usr/local/pgsql/bin/pg_dump --quote-all-identifiers --username=postgres -p 5432 -t $TABLE -h localhost mydb | gzip -1 > $DESTINATION
As you can see, this works for only 1 table, I'm not sure how to pass multiple tables to the sh script (-t table1 -t table2 -t table3 etc)
I could use arrays, but still, not sure how to code this.
Thanks!
If you are willing to make DESTINATION the first expected argument, then something like this should work for you:
DESTINATION=$1
TABLES=`echo ${#:2}|sed "s/\s/ -t /g"`
/usr/local/pgsql/bin/pg_dump --quote-all-identifiers --username=postgres -p 5432 -t $TABLES -h localhost mydb | gzip -1 > $DESTINATION
I am trying to create a shell script to bootstrap new DBs.
I am able to create users, grant privileges and do all actions, except running any queries with passwords. The single quotes in shell script creates statements which postgres is not accepting.
Because of this, we cannot completely automate this process.
Below is one of the postgres line used in shell script.
PGPASSWORD=change123 psql -h $DB -p 5432 -d postgres -U root -c \"CREATE USER $(echo "$j" | cut -d "_" -f1)dbuser WITH PASSWORD \'$(echo $DBPASSWD|base64 --decode)\';\"
When executing the above script, the command is converted as
psql -h testdb -p 5432 -d postgres -U root -c '"CREATE' USER admindbuser WITH PASSWORD ''\''ZnuLEmu72R'\'''
where I want the command to be like
psql -h testdb -p 5432 -d postgres -U root -c "CREATE USER admindbuser WITH PASSWORD 'ZnuLEmu72R';"
Any help is very much appreciated. I want some help in guiding how to modify the line in shell so as to achieve the required command.
Change
PGPASSWORD=change123 psql\
-h $DB \
-p 5432 \
-d postgres \
-U root \
-c \"CREATE USER $(echo "$j" | cut -d "_" -f1)dbuser WITH PASSWORD \'$(echo $DBPASSWD|base64 --decode)\';\"
to
PGPASSWORD=change123 psql \
-h "$DB" \
-p 5432 \
-d postgres \
-U root \
-c "CREATE USER ${j%%_*}dbuser WITH PASSWORD '$(printf '%s' "$DBPASSWD" | base64 --decode)';"
I want to export a random entry of my database into a file with the command
SELECT * FROM my_table ORDER BY RANDOM() LIMIT 1 \g /path/file;
This query works if I enter it in my db terminal, but I want to us this query with a bash script but then I get the error: syntax error at or near "\g"
My bash script looks like this:
PGPASSWORD=*** psql -U user -d db_name -h localhost -p port -t -c "SELECT * FROM my_table ORDER BY RANDOM() LIMIT 1 \g /path/file"
Bash is interpreting the string and trying to interpolate it. Probably, escaping the backslash will solve your problem.
PGPASSWORD=*** psql -U user -d db_name -h localhost -p port -t -c "SELECT * FROM my_table ORDER BY RANDOM() LIMIT 1 \\g /path/file"
A SQL statement terminated by \g is not supported by the -c command switch. Per documentation of -c:
-c command
...
command must be either a command string that is completely parsable by the server (i.e., it contains no psql-specific features), or a single backslash command. Thus you cannot mix SQL
and psql meta-commands with this option
To redirect the results to a file, there are several options:
shell redirection: psql [other options] -Atc 'SELECT...' >/path/to/data.txt
-A is to switch to unaligned mode (no space fillers to align columns).
put the SQL part in a heredoc text instead of the command line:
psql [options] <<EOF
SELECT ... \g /path/to/file
EOF
This form has the advantage that multiline statements or multiple statements are supported directly.
\copy of the query. Be aware that COPY to a FILE is different: it creates the file on the server with the permissions of postgres and requires being a database superuser. COPY TO STDOUT works too but is not better than SELECT concerning the redirection.
I found a solution for my script, and now it works.
#!/bin/bash
RANDOM_NUMBER=0
while true
do
for i in `seq 1`
do
RANDOM_NUMBER=$(($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;"'
I'm trying to get a list of database names using the psql command. So far I have:
psql -h example.com -U backup -c '\l'
This however gives me the results in a table-like format. I ONLY want the table names (one on each line). How would I accomplish this?
This does it:
psql -h example.com -U backup -t -A -c "SELECT datname FROM pg_database WHERE datname <> ALL ('{template0,template1,postgres}')"
Using the system catalog pg_database.
Read the manual about psql.
I don't think you can use \l for that.
But the following should do it:
psql -h example.com -U backup -t -c "select datname from pg_database"
\t turns off the header and the other "noise". And the select statement only returns the database name.
Not sure if you need to use single quotes or double quotes for the SQL statement - on my Windows console I had to use double quotes.