This query creates a cursor which contains one column and as many rows as there are in the table. Value of that column is
1 in all rows.
This is not very useful construct.
I sometimes do use constants in the select clause in more complicated circumstances, eg:
(Note: the
order by 2, 3 causes ordering by second and third column of the resultset. It is useful with
union operator as there could be ambiguity in column names otherwise.)