How to create batch file to execute multiple DB2 queries - db2

I have to run some DB2 SQL queries more frequently.It is taking lot of time to do that manually. For that, I am planning to create batch file to execute those DB2 SQL commands.
So,Please let me know whether it is possible to create windows batch file to run set of DB2 sql queries.

You can save a .sql file to your hard drive, and execute it using the DB2 command line using:
db2 -vtf C:\path\to\somefile.sql
-v echoes the command text back to the command line
-t sets the statement terminator to ;. If you want to use something else (creating stored procedures for example), you can use -td__ where __ represents up to two characters you can use as the terminator. Alternatively, you can use --#SET TERMINATOR __ inside your batch file
-f tells the command line to load the commands from the file.
See other command line options here.

Related

Function/procedure to save a schema as an .sql file in PostgreSQL

I want to create a procedure which when I call creates a backup by creating an .sql file and saves it in my computer.
The procedure's name is trial_gen(). When I execute call trial_gen(), it should create a plain .sql file of the schema.
All solutions I found were only using the SQL shell
SQL code is a script, so I think it makes sense to run one from SQL shell. It would be a stored script (text) in a file anyway.

Creating Batch Files with PostgreSQL \copy Command in Jetbrains Datagrip

I'm familiarizing myself with the standalone version of Datagrip and having a bit of trouble understanding the different approaches to composing SQL via console, external files, scratch files, etc.
I'm managing, referencing the documentation, and am happy to figure things out as such.
However, I'm trying to ingest CSV data into tables via batch files using the Postgres \copy command. Datagrip will execute this command without error but no data is being populated.
This is my syntax, composed and ran in the console view:
\copy tablename from 'C:\Users\username\data_file.txt' WITH DELIMITER E'\t' csv;
Note that the data is tab-separated and stored in a .txt file.
I'm able to use the import functions of Datagrip (via context menu) just fine but I'd like to understand how to issue commands to do similarly.
\copy is a command of the command-line PostgreSQL client psql.
I doubt that Datagrip invokes psql, so it won't be able to use \copy or any other “backslash command”.
You probably have to use Datagrip's import facilities. Or you start using psql.
Ok, but what about the SQL COPY command https://www.postgresql.org/docs/12/sql-copy.html ?
How can I run something like that with datagrip ?
BEGIN;
CREATE TEMPORARY TABLE temp_json(values text) ON COMMIT DROP;
COPY temp_json FROM 'MY_FILE.JSON';
SELECT values->>'aJsonField' as f
FROM (select values::json AS values FROM temp_json) AS a;
COMMIT;
I try to replace 'MY_FILE.JSON' with full path, parameter (?), I put it in sql directory etc.
The data grip answer is :
[2021-05-05 10:30:45] [58P01] ERROR: could not open file '...' for reading : No such file or directory
EDIT :
I know why. RTFM! -_-
COPY with a file name instructs the PostgreSQL server to directly read from or write to a file. The file must be accessible by the PostgreSQL user (the user ID the server runs as) and the name must be specified from the viewpoint of the server.
Sorry.....

how to pass variable to copy command in Postgresql

I tried to make a variable in SQL statement in Postgresql, but it did not work.
There are many csv files stored under the path. I want to set path in Postgresql that can tell copy command where can find csv files.
SQL statement sample:
\set outpath '/home/clients/ats-dev/'
\COPY licenses (_id, name,number_seats ) FROM :outpath + 'licenses.csv' CSV HEADER DELIMITER ',';
\COPY uploaded_files (_id, added_date ) FROM :outpath + 'files.csv' CSV HEADER DELIMITER ',';
It did not work. I got error: no such files. The two files licneses.csv and files.csv are stored under /home/cilents/ats-dev on Ubuntu. I found some sultion that use "\set file 'license.csv'". It did not work for me becacuse I have many csv files. also I tried to use "from : outpath || 'licenses.csv'". it did not work ether. Appreciate for any helps.
Using 9.3.
It looks like psql does not support :variable substitution withinpsql backslash commands.
test=> \set somevar fred
test=> \copy z from :somevar
:somevar: No such file or directory
so you will need to do this via an external tool like the unix shell. e.g.
for f in *.sql; do
psql -c "\\copy $(basename $f) FROM '$f'"
done
You can try COPY command
\set outpath '\'/home/clients/ats-dev/'
COPY licenses (_id, name,number_seats ) FROM :outpath/licenses.csv' WITH CSV HEADER DELIMITER ',';
COPY uploaded_files (_id, added_date ) FROM :outpath/files.csv' WITH CSV HEADER DELIMITER ',';
Note: Files named in a COPY command are read or written directly by the server, not by the client application. Therefore, they must reside on or be accessible to the database server machine, not the client. They must be accessible to and readable or writable by the PostgreSQL user (the user ID the server runs as), not the client. Similarly, the command specified with PROGRAM is executed directly by the server, not by the client application, must be executable by the PostgreSQL user. COPY naming a file or command is only allowed to database superusers, since it allows reading or writing any file that the server has privileges to access.
Documentation: Postgresql 9.3 COPY
It may have been true when this was originally asked, that psql backslash commands didn't support variable interpolation, but in my PostgreSQL 14 instance that's no longer the case. However, the psql manpage is clear that \copy specifically does not support variable interpolation.

Automating PostgreSQL output to csv

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

A script that deletes all tables in Hbase

I can tell hbase to disable and delete particular tables using:
disable 'tablename'
drop 'tablename'
But I want to delete all the tables in the database without hardcoding the names of any of the tables. Is there a way to do this? I want to do this through the command-line utility ./hbase shell, not through Java or Thrift.
disable_all and drop_all have been added as commands in the HBase ruby shell. These commands were added in jira HBASE-3506 These commands take a regex of tables to disable/drop. And they will ask for confirmation before continuing. That should make droping lots of tables pretty easy and not require outside libraries or scripting.
I have a handy script that does exactly this, using the Python Happybase library:
import happybase
c = happybase.Connection()
for table in c.tables():
c.disable_table(table)
c.delete_table(table)
print "Deleted: " + table
You will need Happybase installed to use this script, and you can install it as:
sudo easy_install happybase
You can pipe commands to the bin/hbase shell command. From there you can use some scripting to grab the table names and pipe the disable/delete commands back to hbase.
i.e.
echo "list" | bin/hbase shell | ./filter_table_names.pl > table_names.txt
./turn_table_names_into_disable_delete_commands.pl table_names.txt | bin/hbase shell
There is a hack.
Open $HBASE_HOME/lib/ruby/shell/commands/list.rb file and add below line at the bottom of command method.
return list
After that, list command returns an array of names of all tables.
And then do just like this.
list.each {|t| disable t;drop t}
I'm not deleting tables through the hbase shell but I deleting them from the command line by,
- deleting my hadoop distributed filesystem directory, then,
- creating a new clean hadoop distributed filesystem directory, then,
- formatting my hadoop distributed filesystem with 'hadoop namenode -format', then,
- start-all.sh and start-hbase.sh
Reference:
http://hadoop.apache.org/common/docs/r0.20.1/api/overview-summary.html#overview_description
If you're looking for something that will do this in a 'one-liner' via a shell script you can use this method:
$ echo 'list.each {|t| disable t; drop t}; quit;' | hbase shell
NOTE: The above was run from Bash shell prompt. It echoes the commands into hbase shell and does a loop through all the tables that are returned from the list command, and then disables & drops each table as it iterates through the array that list returned. Once it's done, it quits.