I have a sql script which i run for by-hand status checks of a long running process. My server is currently postgres 10. The script contains a couple dozen queries. However, each query requires the id of the current process (not linux pid, but a column in the db).
So, it's like
SELECT * FROM table1 WHERE id = 'xxx';
SELECT * FROM table2 WHERE id = 'xxx';
... and so forth
I have a sql script that i keep updating with the most recent id, and run with
db# \i my-script.sql
It would be great if I could pass variables into the script. For example, maybe the script is
SELECT * FROM table1 WHERE id = '$1';
SELECT * FROM table2 WHERE id = '$1';
and i could run
db# \i my-script.sql 'xxx'
and it would properly substitute that value for all $1 in the sql script. Bonus points for multiple args (eg $2 and so on).
OTOH, I could write a bash script wrapping psql command line, but I'd need to drop to a shell to execute it - if i'm already in psql, I'm right there.
Any advice?
Thanks!
Use psql variables.
In the script, write
\prompt 'Please enter id:' myid
SELECT * FROM table1 WHERE id = :'myid';
If you don't want an interactive prompt, omit the \prompt and set the variable in the calling script:
\set myid 1234
Related
I'm attempting to dynamically create a script that gets saved as a bat file that will be scheduled to execute daily via Windows Task Scheduler. The script performs full database backups for each Postgres database using pg_dump.
The current script is as follows:
COPY (SELECT 'pg_dump '|| datname || ' > e:\postgresbackups\FULL\' || datname || '_%date:~4,2%-%date:~7,2%-%date:~10,4%_%time:~0,2%_%time:~3,2%_%time:~6,2%.dump' FROM pg_database) TO 'E:\PostgresBackups\Script\FULL_Postgres_Backup_Job_TEST.bat' (format csv, delimiter ';');
An example of the output is as follows:
pg_dump postgres > e:\postgresbackups\FULL\postgres_%date:~4,2%-%date:~7,2%-%date:~10,4%%time:~0,2%%time:~3,2%_%time:~6,2%.dump
I need help with updating my code so that the output will include double quotes around the name of the dump file; however, when I add this to my COPY script it adds more than what is necessary to the output. I would like the output to look like the following which includes the double-quotes:
pg_dump postgres > "e:\postgresbackups\FULL\postgres_%date:~4,2%-%date:~7,2%-%date:~10,4%%time:~0,2%%time:~3,2%_%time:~6,2%.dump"
Any help would be greatly appreciated!
Thanks to #Mike Organek's comment, my issue has been resolved by switching the format from CSV to TEXT. Now when I enclose the dump filename in double quotes, the output is more of what is expected and works as intended. The only odd thing now is that in the output it creates a second backslash in the filename. My code has been updated as follows:
COPY (SELECT 'pg_dump '|| datname || ' > "e:\postgresbackups\FULL\' || datname || '_%date:~4,2%-%date:~7,2%-%date:~10,4%_%time:~0,2%_%time:~3,2%_%time:~6,2%.dump"' FROM pg_database) TO 'E:\PostgresBackups\Script\FULL_Postgres_Backup_Job.bat' (format text, delimiter ';');
An example of the output that gets created within the bat file is as follows:
pg_dump postgres > "e:\\postgresbackups\\FULL\\postgres_%date:~4,2%-%date:~7,2%-%date:~10,4%_%time:~0,2%_%time:~3,2%_%time:~6,2%.dump"
As you can see, it adds a double backslash; however, the pg_dump executes successfully!
i'm learning psql in Postgres.
My basic question is when i create a function like this one :
CREATE OR REPLACE FUNCTION totalRecords ()
RETURNS integer AS $total$
declare
total integer;
BEGIN
SELECT count(*) into total FROM COMPANY;
RETURN total;
END;
$total$ LANGUAGE plpgsql;
i must write all of the code in the prompt command line.
How can i save this code in a script and call it from the command line ? the extentsion of the scirpt must be a .sql ? how can i call this script.
Save your script to a file. Then execute like this:
psql -p portnumber -d database -U user -f mysqlscrpt.sql
The extension of the script does not matter.
#jkdba's answer is sufficient but, alternatively, if you are already logged in the psql console, you can use:
\i <sqlscript>.sql
The \i being for input. \o is output, and it would write to the file instead of bringing it in.
I mention this because this is what made me remember the command :)
is possible in PSQL console export file with current date on the end of the file name?
The name of the exported file should be like this table_20140710.csv is it possible to do this dynamically? - the format of the date can be different than the above it isn't so much important.
This is example what i mean:
\set curdate current_date
\copy (SELECT * FROM table) To 'C:/users/user/desktop/table_ ' || :curdate || '.csv' WITH DELIMITER AS ';' CSV HEADER
The exception of the \copy meta command not expanding variables is (meanwhile) documented
Unlike most other meta-commands, the entire remainder of the line is always taken to be the arguments of \copy, and neither variable interpolation nor backquote expansion are performed in the arguments.
To workaround you can build, store and execute the command in multiple steps (similar to the solution Clodoaldo Neto has given):
\set filename 'my fancy dynamic name'
\set command '\\copy (SELECT * FROM generate_series(1, 5)) to ' :'filename'
:command
With this, you need to double (escape) the \ in the embedded meta command. Keep in mind that \set concatenates all further arguments to the second one, so quote spaces between the arguments. You can show the command before execution (:command) with \echo :command.
As an alternative to the local \set command, you could also build the command server side with SQL (the best way depends on where the dynamic content is originating):
SELECT '\copy (SELECT * FROM generate_series(1, 5)) to ''' || :'filename' || '''' AS command \gset
Dynamically build the \copy command and store it in a file. Then execute it with \i
First set tuples only output
\t
Set the output to a file
\o 'C:/users/user/desktop/copy_command.txt'
Build the \copy command
select format(
$$\copy (select * from the_table) To 'C:/users/user/desktop/table_%s.csv' WITH DELIMITER AS ';' CSV HEADER$$
, current_date
);
Restore the output to stdout
\o
Execute the generated command from the file
\i 'C:/users/user/desktop/copy_command.txt'
mohpc04pp1: /h/u544835 % psql arco
Welcome to psql 8.1.17, the PostgreSQL interactive terminal.
Type: \copyright for distribution terms
\h for help with SQL commands
\? for help with psql commands
\g or terminate with semicolon to execute query
\q to quit
WARNING: You are connected to a server with major version 8.3,
but your psql client is major version 8.2. Some backslash commands,
such as \d, might not work properly.
dbname=> \o /h/u544835/data25000.csv
dbname=> select url from urltable where scoreid=1 limit 25000;
dbname=> \q
This is took from a link online of basically what I have been doing, but what I need to do is make a script that I can use to produce csv files daily
So my aim of the script is to while in the script connect to the db, run the \o etc commands then close it
but I'm having trouble scripting it to say go into the psql arco database then run those queries.
command line to connect to db = psql arco then once the scrits recognised I'm in that databse perform those commands to automate a query to a csv file.
if anyone can get me started or point me towards reading material for me to get past that bit, it will be duely appreciated.
i'm running all this off a standard windows xp, ssh'ing to a SLES set-up web server that holds my postgresql database running psql version 8.1.17
First of all you should fix your setup. As it turns out, we are dealing with PostgreSQL 8.1 here. This version has reached end of live in 2010. You need to seriously think about upgrading - or at least remind the guys running the server. Current version is 9.1.
The command you are looking for:
psql arco -c "\copy (select url from urltable where scoreid=1 limit 25000) to '/h/u544835/data25000.csv'"
Assuming your db is named "arco". Adjusted for changed question (including changed port).
I now see version 8.1 popping up in your question, but it's all contradictory. You need Postgres 8.2 or later to use a query (instead of a table) with the \copy meta-command.
Details about psql in the fine manual.
Alternative approach that should work with obsolete PostgreSQL 8.1:
psql arco -o /h/u544835/data25000.csv -t -A -c 'SELECT url FROM urltable WHERE scoreid = 1 LIMIT 25000'
Find some more info about these command line options under this related question on dba.SE.
With function (syntax compatible with 8.1)
Another way would be to create a server side function (if you can!) that executes COPY from a temp table (old syntax - works with pg 8.1):
CREATE OR REPLACE FUNCTION f_copy_file()
RETURNS void AS
$BODY$
BEGIN
CREATE TEMP TABLE u_tmp AS (
SELECT url FROM urltable WHERE scoreid = 1 LIMIT 25000
);
COPY u_tmp TO '/h/u544835/data25000.csv';
DROP TABLE u_tmp;
END;
$BODY$
LANGUAGE plpgsql;
And then from the shell:
psql arco -c 'SELECT f_copy_file()'
Change the separator
\f sets the field separator. I quote the manual again:
-F separator
--field-separator=separator
Use separator as the field separator for unaligned output.
This is equivalent to \pset fieldsep or \f.
Or you can change the column separator in Excel, here are the instructions from MS.
Thanks to Erwin's help and a link I read up on he posted for me I managed to combine the two to get
#!/bin/sh
dbname='arco'
username='' # If you actually supply a username, you need to add the -U switch!
psql $dbname $username << EOF
\f ,
\o /h/u544835/showme.csv
SELECT * FROM storage;
EOF
which will write my queries to a csv file etc for me.
From what there is above, it is not separating the sql query so if I load it straight into excel, they all stay in the same column too which means I'm having a problem with the delimiter
I've tried tabbed delimiters, also tried , ; etc but none are letting me separate it
I need for it
is there an option I can click to see which delimiter is being used with my psql? or a different way of dumping the data from a query into a file that can be read by excel, so a different column for each row etc
I am not a programmer, I am struggling a bit with this.
I have a batch file connecting to my PostgreSQL server, and then open a sql script. Everything works as expected. My question is how to pass a variable (if possible) from one to the other.
Here is my batch file:
set PGPASSWORD=xxxx
cls
#echo off
C:\Progra~1\PostgreSQL\8.3\bin\psql -d Total -h localhost -p 5432 -U postgres -f C:\TotalProteinImport.sql
And here's the script:
copy totalprotein from 'c:/TP.csv' DELIMITERS ',' CSV HEADER;
update anagrafica
set pt=(select totalprotein.resultvalue from totalprotein where totalprotein.accessionnbr=anagrafica.id)
where data_analisi = '12/23/2011';
delete from totalprotein;
This is working great, now the question is how could I pass a variable that would carry the date for data_analisi?
Like in the batch file, "Please enter date", and then the value is passed to the sql script.
You could create a function out of your your SQL script like this:
CREATE OR REPLACE FUNCTION f_myfunc(date)
RETURNS void AS
$BODY$
CREATE TEMP TABLE t_tmp ON COMMIT DROP AS
SELECT * FROM totalprotein LIMIT 0; -- copy table-structure from table
COPY t_tmp FROM 'c:/TP.csv' DELIMITERS ',' CSV HEADER;
UPDATE anagrafica a
SET pt = t.resultvalue
FROM t_tmp t
WHERE a.data_analisi = $1
AND t.accessionnbr = a.id;
-- Temp table is dropped automatically at end of session
-- In this case (ON COMMIT DROP) after the transaction
$BODY$
LANGUAGE sql;
You can use language SQL for this kind of simple SQL batch.
As you can see I have made a couple of modifications to your script that should make it faster, cleaner and safer.
Major points
For reading data into an empty table temporarily, use a temporary table. Saves a lot of disc writes and is much faster.
To simplify the process I use your existing table totalprotein as template for the creation of the (empty) temp table.
If you want to delete all rows of a table use TRUNCATE instead of DELETE FROM. Much faster. In this particular case, you need neither. The temporary table is dropped automatically. See comments in function.
The way you updated anagrafica.pt you would set the column to NULL, if anything goes wrong in the process (date not found, wrong date, id not found ...). The way I rewrote the UPDATE, it only happens if matching data are found. I assume that is what you actually want.
Then ask for user input in your shell script and call the function with the date as parameter. That's how it could work in a Linux shell (as user postgres, with password-less access (using IDENT method in pg_haba.conf):
#! /bin/sh
# Ask for date. 'YYYY-MM-DD' = ISO date-format, valid with any postgres locale.
echo -n "Enter date in the form YYYY-MM-DD and press [ENTER]: "
read date
# check validity of $date ...
psql db -p5432 -c "SELECT f_myfunc('$date')"
-c makes psql execute a singe SQL command and then exits. I wrote a lot more on psql and its command line options yesterday in a somewhat related answer.
The creation of the according Windows batch file remains as exercise for you.
Call under Windows
The error message tells you:
Function tpimport(unknown) does not exist
Note the lower case letters: tpimport. I suspect you used mixe case letters to create the function. So now you have to enclose the function name in double quotes every time you use it.
Try this one (edited quotes!):
C:\Progra~1\PostgreSQL\8.3\bin\psql -d Total -h localhost -p 5432 -U postgres
-c "SELECT ""TPImport""('%dateimport%')"
Note how I use singe and double quotes here. I guess this could work under windows. See here.
You made it hard for yourself when you chose to use mixed case identifiers in PostgreSQL - a folly which I never tire of warning against. Now you have to double quote the function name "TPImport" every time you use it. While perfectly legit, I would never do that. I use lower case letters for identifiers. Always. This way I never mix up lower / upper case and I never have to use double quotes.
The ultimate fix would be to recreate the function with a lower case name (just leave away the double quotes and it will be folded to lower case automatically). Then the function name will just work without any quoting.
Read the basics about identifiers here.
Also, consider upgrading to a more recent version of PostgreSQL 8.3 is a bit rusty by now.
psql supports textual replacement variables. Within psql they can be set using \set and used using :varname.
\set xyz 'abcdef'
select :'xyz';
?column?
----------
abcdef
These variables can be set using command line arguments also:
psql -v xyz=value
The only problem is that these textual replacements always need some fiddling with quoting as shown by the first \set and select.
After creating the function in Postgres, you must create a .bat file in the bin directory of your Postgres version, for example C:\Program Files\PostgreSQL\9.3\bin. Here you write:
#echo off
cd C:\Program Files\PostgreSQL\9.3\bin
psql -p 5432 -h localhost -d myDataBase -U postgres -c "select * from myFunction()"