How to select multiple row in postgresql?

Question

I can give a result set consisting of a single value, say 1, as follows:

SELECT 1 as column;

and it gives me the result set:

column
------
  1

But I have a list of such values represented as a string (1, 4, 7, ...) and I need to produce the following result set:

column
------
  1
  4
  7
  .
  .
  .

I tried SELECT * FROM (1, 4, 7) but it didn't work. I also tried to SELECT 1, 4, 7 but it produces the following result set:

col1   col2    col3
 1       4      7

Which was not what I was looking for.

Answer 1

If those are constant values, you can use the values clause:

select * 
from (
   values (1), (4), (7)
) as t(id);

If your values are inside a string literal, you can use this:

select *
from unnest(string_to_array('1,2,3,4', ',')) as id;