SQL Populate table with random data - sql

Question

I have a table with two fields:
id(UUID) that is primary Key and
description (var255)
I want to insert random data with SQL sentence.
I would like that description would be something random.
PS: I am using PostgreSQL.

Answer 1

I dont know exactly if this fits the requirement for a "random description", and it's not clear if you want to generate the full data: but, for example, this generates 10 records with consecutive ids and random texts:
test=# SELECT generate_series(1,10) AS id, md5(random()::text) AS descr;
id | descr
----+----------------------------------
1 | 65c141ee1fdeb269d2e393cb1d3e1c09
2 | 269638b9061149e9228d1b2718cb035e
3 | 020bce01ba6a6623702c4da1bc6d556e
4 | 18fad4813efe3dcdb388d7d8c4b6d3b4
5 | a7859b3bcf7ff11f921ceef58dc1e5b5
6 | 63691d4a20f7f23843503349c32aa08c
7 | ca317278d40f2f3ac81224f6996d1c57
8 | bb4a284e1c53775a02ebd6ec91bbb847
9 | b444b5ea7966cd76174a618ec0bb9901
10 | 800495c53976f60641fb4d486be61dc6
(10 rows)

Answer 2

The following worked for me:
create table t_random as select s, md5(random()::text) from generate_Series(1,5) s;

Answer 3

Here it is a more elegant way using the latest features. I will use the Unix dictionary (/usr/share/dict/words) and copy it into my PostgreSQL data:
cp /usr/share/dict/words data/pg95/words.list
Then, you can easily create a ton of no sense description BUT searchable using dictionary words with the following steps:
1) Create table and function. getNArrayS gets all the elements in an array and teh number of times it needs to concatenate.
CREATE TABLE randomTable(id serial PRIMARY KEY, description text);
CREATE OR REPLACE FUNCTION getNArrayS(el text[], count int) RETURNS text AS $$
SELECT string_agg(el[random()*(array_length(el,1)-1)+1], ' ') FROM generate_series(1,count) g(i)
$$
VOLATILE
LANGUAGE SQL;
Once you have all in place, run the insert using CTE:
WITH t(ray) AS(
SELECT (string_to_array(pg_read_file('words.list')::text,E'\n'))
)
INSERT INTO randomTable(description)
SELECT getNArrayS(T.ray, 3) FROM T, generate_series(1,10000);
And now, select as usual:
postgres=# select * from randomtable limit 3;
id | description
----+---------------------------------------------
1 | ultracentenarian splenodiagnosis manurially
2 | insequent monopolarity funipendulous
3 | ruminate geodic unconcludable
(3 rows)

Answer 4

I assume sentance == statement? You could use perl or plperl as perl has some good random data generators. Check out perl CPAN module Data::Random to start.
Here's a sample of a perl script to generate some different random stuff taken from CPAN.
use Data::Random qw(:all);
my #random_words = rand_words( size => 10 );
my #random_chars = rand_chars( set => 'all', min => 5, max => 8 );
my #random_set = rand_set( set => \#set, size => 5 );
my $random_enum = rand_enum( set => \#set );
my $random_date = rand_date();
my $random_time = rand_time();
my $random_datetime = rand_datetime();
open(FILE, ">rand_image.png") or die $!;
binmode(FILE);
print FILE rand_image( bgcolor => [0, 0, 0] );
close(FILE);