This section describes functions that possibly return more than one row.
Currently the only functions in this class are series generating functions,
as detailed in Table 9-38.
Table 9-38. Series Generating Functions
| Function | Argument Type | Return Type | Description |
|---|
generate_series(start, stop) | int or bigint | setof int or setof bigint (same as argument type) | Generate a series of values, from start to stop
with a step size of one
|
generate_series(start, stop, step) | int or bigint | setof int or setof bigint (same as argument type) | Generate a series of values, from start to stop
with a step size of step
|
When step is positive, zero rows are returned if
start is greater than stop.
Conversely, when step is negative, zero rows are
returned if start is less than stop.
Zero rows are also returned for NULL inputs. It is an error
for step to be zero. Some examples follow:
select * from generate_series(2,4);
generate_series
-----------------
2
3
4
(3 rows)
select * from generate_series(5,1,-2);
generate_series
-----------------
5
3
1
(3 rows)
select * from generate_series(4,3);
generate_series
-----------------
(0 rows)
select current_date + s.a as dates from generate_series(0,14,7) as s(a);
dates
------------
2004-02-05
2004-02-12
2004-02-19
(3 rows)
