1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
|
--
-- Test returning SETOF
--
CREATE FUNCTION test_setof_error() RETURNS SETOF text AS $$
return 37
$$ LANGUAGE plpythonu;
SELECT test_setof_error();
ERROR: returned object cannot be iterated
DETAIL: PL/Python set-returning functions must return an iterable object.
CONTEXT: PL/Python function "test_setof_error"
CREATE FUNCTION test_setof_as_list(count integer, content text) RETURNS SETOF text AS $$
return [ content ]*count
$$ LANGUAGE plpythonu;
CREATE FUNCTION test_setof_as_tuple(count integer, content text) RETURNS SETOF text AS $$
t = ()
for i in range(count):
t += ( content, )
return t
$$ LANGUAGE plpythonu;
CREATE FUNCTION test_setof_as_iterator(count integer, content text) RETURNS SETOF text AS $$
class producer:
def __init__ (self, icount, icontent):
self.icontent = icontent
self.icount = icount
def __iter__ (self):
return self
def next (self):
if self.icount == 0:
raise StopIteration
self.icount -= 1
return self.icontent
return producer(count, content)
$$ LANGUAGE plpythonu;
CREATE FUNCTION test_setof_spi_in_iterator() RETURNS SETOF text AS
$$
for s in ('Hello', 'Brave', 'New', 'World'):
plpy.execute('select 1')
yield s
plpy.execute('select 2')
$$
LANGUAGE plpythonu;
-- Test set returning functions
SELECT test_setof_as_list(0, 'list');
test_setof_as_list
--------------------
(0 rows)
SELECT test_setof_as_list(1, 'list');
test_setof_as_list
--------------------
list
(1 row)
SELECT test_setof_as_list(2, 'list');
test_setof_as_list
--------------------
list
list
(2 rows)
SELECT test_setof_as_list(2, null);
test_setof_as_list
--------------------
(2 rows)
SELECT test_setof_as_tuple(0, 'tuple');
test_setof_as_tuple
---------------------
(0 rows)
SELECT test_setof_as_tuple(1, 'tuple');
test_setof_as_tuple
---------------------
tuple
(1 row)
SELECT test_setof_as_tuple(2, 'tuple');
test_setof_as_tuple
---------------------
tuple
tuple
(2 rows)
SELECT test_setof_as_tuple(2, null);
test_setof_as_tuple
---------------------
(2 rows)
SELECT test_setof_as_iterator(0, 'list');
test_setof_as_iterator
------------------------
(0 rows)
SELECT test_setof_as_iterator(1, 'list');
test_setof_as_iterator
------------------------
list
(1 row)
SELECT test_setof_as_iterator(2, 'list');
test_setof_as_iterator
------------------------
list
list
(2 rows)
SELECT test_setof_as_iterator(2, null);
test_setof_as_iterator
------------------------
(2 rows)
SELECT test_setof_spi_in_iterator();
test_setof_spi_in_iterator
----------------------------
Hello
Brave
New
World
(4 rows)
|
