Trying to understand why same SQL returns different results.

From: Neil Tiffin <neilt(at)neiltiffin(dot)com>
To: psycopg(at)postgresql(dot)org
Subject: Trying to understand why same SQL returns different results.
Date: 2012-11-20 20:33:18
Message-ID: 2EEC5FA1-EEEE-4A03-A17A-1DC0724689C7@neiltiffin.com
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When I run the SQL directly from psycopg and from a plpgsql function each produces different results. One returns two columns and the other only returns one column.

For example.

def sql_test1():
cur = CONN.cursor()
cur.execute("""
CREATE OR REPLACE FUNCTION get_some_text()
RETURNS RECORD AS $$
DECLARE
result RECORD;
BEGIN
SELECT 'some text' AS colume1, 'some more text' as column2 INTO result;
RETURN result;
END;
$$ LANGUAGE plpgsql;""")

print('test 1')
cur.execute("""SELECT 'some text' AS colume1, 'some more text' as column2;""")
print (cur.description)
print (cur.fetchone())

print ('test 2')
cur.execute("""SELECT get_some_text();""")
print (cur.description)
print (cur.fetchone())

CONN.commit()
cur.close()

Output:
test 1
(Column(name='colume1', type_code=705, display_size=None, internal_size=-2, precision=None, scale=None, null_ok=None), Column(name='column2', type_code=705, display_size=None, internal_size=-2, precision=None, scale=None, null_ok=None))
('some text', 'some more text')

test 2
(Column(name='get_some_text', type_code=2249, display_size=None, internal_size=-1, precision=None, scale=None, null_ok=None),)
('("some text","some more text")',)

Is this the expected results and I am misunderstanding something? Or is this a bug?

Neil

Python 3.3.0
Mac OS X 10.7.5, Postgresql 9.1.2, psycopg git clone,

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