i want to import this postgreSQL output to file - postgresql

the following code is correct ?
i want to store foo table output to file.txt file how to write shell script for this
psql <<EOF
\pset format wrapped
SELECT * FROM foo;
EOF |tee -a file.txt

Related

I want to update a file with rollno. and name from a csv file where name and roll no are separated by comma

My input file is a csv file containing details as:
2233,anish sharma
2234,azad khan
2235,birbal singh
2236,chaitanya kumar
my expected output is display of the two details in two separate columns.
I executed following code. Full name is not getting displayed. The part after space doesn't appear. What changes should be done?
echo "Roll no updation"
tput cup 10 10
echo "Key in file name (rollno,name separated by comma)"
tput cup 12 10
read infile
for i in `cat $infile`
do
rollno=`echo $i|cut -d , -f1`
name=`echo $i|cut -d , -f2`
psql -U postgres -A -t -F, -c "update student set name = '$name' where rollno = '$rollno' current record" >bq
done
Your loop should be written in this fashion
# comma separates records
IFS=,
cat "$infile" | while read rollno name; do
psql -U postgres -A -t -F, -c \
"update student set name = '$name'
where rollno = '$rollno'" >bq
done
But you should be aware that this code is susceptible to SQL injection. Only use it if you can trust the source of the data!
Any ' in the file will cause errors and worse.

psql - read SQL file and output to CSV

I have a SQL file my_query.sql:
select * from my_table
Using psql, I can read in this sql file:
\i my_query.sql
Or pass it in as an arg:
psql -f my_query.sql
And I can output the results of a query string to a csv:
\copy (select * from my_table) to 'output.csv' with csv header
Is there a way to combine these so I can output the results of a query from a SQL file to a CSV?
Unfortunately there's no baked-in functionality for this, so you need a little bash-fu to get this to work properly.
CONN="psql -U my_user -d my_db"
QUERY="$(sed 's/;//g;/^--/ d;s/--.*//g;' my_query.sql | tr '\n' ' ')"
echo "\\copy ($QUERY) to 'out.csv' with CSV HEADER" | $CONN
The sed fun removes all semicolons, comment lines, and end of line comments, and tr converts newlines to spaces (as mentioned in a comment by #abelisto):
-- my_query.sql
select *
from my_table
where timestamp < current_date -- only want today's records
limit 10;
becomes:
select * from my_table where timestamp < current_date limit 10
which then gets passed in to the valid psql command:
\copy (select * from my_table where timestamp < current_date) to 'out.csv' with csv header
Here's a script:
sql_to_csv.sh
#!/bin/bash
# sql_to_csv.sh
CONN="psql -U my_user -d my_db"
QUERY="$(sed 's/;//g;/^--/ d;s/--.*//g;' $1 | tr '\n' ' ')"
echo "$QUERY"
echo "\\copy ($QUERY) to '$2' with csv header" | $CONN > /dev/null
./sql_to_csv.sh my_query.sql out.csv
I think the simplest way is to take advantage of the shell's variable expansion capabilities:
psql -U my_user -d my_db -c "COPY ($(cat my_query.sql)) TO STDOUT WITH CSV HEADER" > my_query_results.csv
You could do it using a bash script.
dump_query_to_csv.sh:
#!/bin/bash
# Takes an sql query file as an argument and dumps its results
# to a CSV file using psql \copy command.
#
# Usage:
#
# dump_query_to_csv.sh <sql_query_file> [<csv_output_filesname>]
SQL_FILE=$1
[ -z $SQL_FILE ] && echo "Must supply query file" && exit
shift
OUT_FILE=$1
[ -z $OUT_FILE ] && OUT_FILE="output.csv" # default to "output.csv" if no argument is passed
TMP_TABLE=ttt_temp_table_xx # some table name that will not collide with existing tables
## Build a psql script to do the work
PSQL_SCRIPT=temp.psql
# create a temporary database table using the SQL from the query file
echo "DROP TABLE IF EXISTS $TMP_TABLE;CREATE TABLE $TMP_TABLE AS" > $PSQL_SCRIPT
cat $SQL_FILE >> $PSQL_SCRIPT
echo ";" >> $PSQL_SCRIPT
# copy the temporary table to the output CSV file
echo "\copy (select * from $TMP_TABLE) to '$OUT_FILE' with csv header" >> $PSQL_SCRIPT
# drop the temporary table
echo "DROP TABLE IF EXISTS $TMP_TABLE;" >> temp.sql
## Run psql script using psql
psql my_database < $PSQL_SCRIPT # replace my_database and add user login credentials as necessary
## Remove the psql script
rm $PSQL_SCRIPT
You'll need to edit the psql line in the script to connect to your database. The script could also be enhanced to take the database and account credentials as arguments.
The accepted solution is correct, but I had Windows and had to make it run via a batch (command) file. Posting it here if someone needs that
#echo off
echo 'Reading file %1'
set CONN="C:\Program Files\PostgreSQL\11\bin\psql.exe" -U dbusername -d mydbname
"C:\Program Files\Git\usr\bin\sed.exe" 's/;//g;/^--/ d;s/--.*//g;' %1 | "C:\Program Files\Git\usr\bin\tr.exe" '\n' ' ' > c:\temp\query.txt
set /p QUERY=<c:\temp\query.txt
echo %QUERY%
echo \copy (%QUERY%) to '%2' WITH (FORMAT CSV, HEADER) | %CONN%

Export from PostgreSQL multiple times to same file

Is it possible to export a table to csv, but to append multiple selections to the same file?
I would like to export (for instance):
SELECT * FROM TABLE WHERE a > 5
Then, later:
SELECT * FROM TABLE WHERE b > 2
This must go to the same file.
Thanks in advance!
The only way that I know of to do this is from the command-line, redirecting output.
psql -d dbname -t -A -F"," -c "SELECT * FROM TABLE WHERE a > 5" >> output.csv
then later
psql -d dbname -t -A -F"," -c "SELECT * FROM TABLE WHERE b > 2" >> output.csv
You can look up the command line options here.
http://www.postgresql.org/docs/9.0/static/app-psql.html
Use \o <filename> to output to a file. All your SELECT statements after using \o will be appended to <file> until you set \o to something else.
Using \o in combination with \copy to STDOUT seems to work. For example:
db=> \o /tmp/test.csv
db=> \copy (select 'foo','bar') to STDOUT with CSV;
db=> \copy (select 'foo','bar') to STDOUT with CSV;
db=> \q
$ cat /tmp/test.csv
foo,bar
foo,bar

mongoimport: append source field

With mongoimport I import the data of several external instances.
Does mongoimport allow me to add a field like source:"where-the-data-comes-from" to each document which is imported?
I.e. if i import the data of server A and B, I would like to store source:"A" or source:"B" to each document.
No. However, you can do this from the command line. Create a file 'header.txt' containing, e.g., (you can create this from your existing csv) by running
cat <(head -1 test.csv | tr "," "\n") <(echo source-a) > header.txt
header.txt should look like this:
field_a
field_b
.......
source
*note I have appended a 'source' field to this document.
Now you can run the command (assuming you have sed installed)
sed 's/$/,source-a/' test.csv | mongoimport -d test-db -c test-cl --type csv --fieldFile header.txt
If you already have a header line in your document, run
sed '1d' test.csv | sed 's/$/,source-a/' | mongoimport -d test -c test --type csv --fieldFile header.txt instead - where 'source-a' is the label you want with this document.
You can easily script this in bash so that you only supply the source and csv for each import job.

Convert pipe delimited csv to tab delimited using batch script

I am trying to write a batch script that will query a Postgres database and output the results to a csv. Currently, it queries the database and saves the output as a pipe delimited csv.
I want the output to be tab delimited rather than pipe delimited, since I will eventually be importing the csv into Access. Does anyone know how this can be achieved?
Current code:
cd C:\Program Files\PostgreSQL\9.1\bin
psql -c "SELECT * from jivedw_day;" -U postgres -A -o sample.csv cscanalytics
postgres = username
cscanalytics = database
You should be using COPY to dump CSV:
psql -c "copy jivedw_day to stdout csv delimiter E'\t'" -o sample.csv -U postgres -d csvanalytics
The delimiter E'\t' part will get you your output with tabs instead of commas as the delimiter. There are other other options as well, please see the documentation for further details.
Using -A like you are just dumps the usual interactive output to sample.csv without the normal padding to making the columns line up, that's why you're seeing the pipes:
-A
--no-align
Switches to unaligned output mode. (The default output mode is otherwise aligned.)