How can I generate a series of repeating numbers in PostgreSQL?

Question

In PostgreSQL, is it possible to generate a series of repeating numbers? For example, I want to generate the numbers 1 to 10, with each number repeated 3 times:

Answer 1

Just another options:

select generate_series(1, 3) from generate_series(1, 10)

select generate_series(1, 30) % 10 + 1

Answer 2

For such small numbers CROSS JOIN two VALUES expressions:

SELECT n
FROM  (VALUES (1),(2),(3)) x(r)  -- repetitions (values are not used)
     ,(VALUES (1),(2),(3),(4),(5),(6),(7),(8),(9),(10)) y(n); -- numbers

SQL Fiddle.

This works for any sequence of numbers (including repeated or irregular patterns).
For anything bigger and with regular sequential pattern use generate_series() as has been suggested.

Answer 3

You could try integer division like this:

SELECT generate_series(3, 100) / 3

Answer 4

You could cross join it to a series of 3:

SELECT a.n
from generate_series(1, 100) as a(n), generate_series(1, 3)

Answer 5

I don't know if you can do use generate_series like that in PostgreSQL, but i would try a cross join:

SELECT x FROM
  (SELECT generate_series(1, 10) AS x) t1, 
  (SELECT generate_series(1, 3) as y) t2

Edit:

As generate_series already returns a table there's no need for SELECT in a Derived Table:

SELECT x FROM
  generate_series(1, 10) AS x, 
  generate_series(1, 3) as y

Answer 6

SELECT a.x from generate_series(0, 100) as a(x), generate_series(1, 3)