mirror of https://github.com/postgres/postgres
This allows functions with multiple OUT parameters returning both one or multiple records (RECORD or SETOF RECORD). Jan Urbański, reviewed by Hitoshi Haradapull/1/head
Peter Eisentraut
15 years ago
parent
772dcfe7c0
commit
bc411f25c1
@ -0,0 +1,361 @@ |
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CREATE FUNCTION multiout_simple(OUT i integer, OUT j integer) AS $$ |
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return (1, 2) |
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$$ LANGUAGE plpythonu; |
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SELECT multiout_simple(); |
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multiout_simple |
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----------------- |
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(1,2) |
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(1 row) |
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|
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SELECT * FROM multiout_simple(); |
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i | j |
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---+--- |
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1 | 2 |
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(1 row) |
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|
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SELECT i, j + 2 FROM multiout_simple(); |
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i | ?column? |
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---+---------- |
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1 | 4 |
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(1 row) |
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|
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SELECT (multiout_simple()).j + 3; |
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?column? |
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---------- |
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5 |
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(1 row) |
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|
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CREATE FUNCTION multiout_simple_setof(n integer = 1, OUT integer, OUT integer) RETURNS SETOF record AS $$ |
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return [(1, 2)] * n |
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$$ LANGUAGE plpythonu; |
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SELECT multiout_simple_setof(); |
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multiout_simple_setof |
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----------------------- |
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(1,2) |
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(1 row) |
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|
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SELECT * FROM multiout_simple_setof(); |
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column1 | column2 |
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---------+--------- |
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1 | 2 |
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(1 row) |
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|
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SELECT * FROM multiout_simple_setof(3); |
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column1 | column2 |
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---------+--------- |
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1 | 2 |
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1 | 2 |
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1 | 2 |
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(3 rows) |
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|
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CREATE FUNCTION multiout_record_as(typ text, |
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first text, OUT first text, |
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second integer, OUT second integer, |
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retnull boolean) RETURNS record AS $$ |
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if retnull: |
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return None |
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if typ == 'dict': |
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return { 'first': first, 'second': second, 'additionalfield': 'must not cause trouble' } |
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elif typ == 'tuple': |
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return ( first, second ) |
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elif typ == 'list': |
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return [ first, second ] |
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elif typ == 'obj': |
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class type_record: pass |
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type_record.first = first |
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type_record.second = second |
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return type_record |
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$$ LANGUAGE plpythonu; |
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SELECT * FROM multiout_record_as('dict', 'foo', 1, 'f'); |
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first | second |
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-------+-------- |
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foo | 1 |
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(1 row) |
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|
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SELECT multiout_record_as('dict', 'foo', 1, 'f'); |
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multiout_record_as |
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-------------------- |
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(foo,1) |
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(1 row) |
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|
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SELECT *, s IS NULL AS snull FROM multiout_record_as('tuple', 'xxx', NULL, 'f') AS f(f, s); |
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f | s | snull |
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-----+---+------- |
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xxx | | t |
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(1 row) |
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|
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SELECT *, f IS NULL AS fnull, s IS NULL AS snull FROM multiout_record_as('tuple', 'xxx', 1, 't') AS f(f, s); |
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f | s | fnull | snull |
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---+---+-------+------- |
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| | t | t |
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(1 row) |
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|
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SELECT * FROM multiout_record_as('obj', NULL, 10, 'f'); |
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first | second |
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-------+-------- |
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| 10 |
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(1 row) |
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|
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CREATE FUNCTION multiout_setof(n integer, |
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OUT power_of_2 integer, |
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OUT length integer) RETURNS SETOF record AS $$ |
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for i in range(n): |
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power = 2 ** i |
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length = plpy.execute("select length('%d')" % power)[0]['length'] |
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yield power, length |
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$$ LANGUAGE plpythonu; |
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SELECT * FROM multiout_setof(3); |
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power_of_2 | length |
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------------+-------- |
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1 | 1 |
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2 | 1 |
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4 | 1 |
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(3 rows) |
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|
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SELECT multiout_setof(5); |
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multiout_setof |
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---------------- |
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(1,1) |
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(2,1) |
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(4,1) |
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(8,1) |
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(16,2) |
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(5 rows) |
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|
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CREATE FUNCTION multiout_return_table() RETURNS TABLE (x integer, y text) AS $$ |
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return [{'x': 4, 'y' :'four'}, |
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{'x': 7, 'y' :'seven'}, |
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{'x': 0, 'y' :'zero'}] |
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$$ LANGUAGE plpythonu; |
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SELECT * FROM multiout_return_table(); |
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x | y |
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---+------- |
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4 | four |
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7 | seven |
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0 | zero |
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(3 rows) |
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|
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CREATE FUNCTION multiout_array(OUT integer[], OUT text) RETURNS SETOF record AS $$ |
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yield [[1], 'a'] |
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yield [[1,2], 'b'] |
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yield [[1,2,3], None] |
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$$ LANGUAGE plpythonu; |
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SELECT * FROM multiout_array(); |
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column1 | column2 |
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---------+--------- |
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{1} | a |
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{1,2} | b |
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{1,2,3} | |
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(3 rows) |
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|
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CREATE FUNCTION singleout_composite(OUT type_record) AS $$ |
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return {'first': 1, 'second': 2} |
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$$ LANGUAGE plpythonu; |
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CREATE FUNCTION multiout_composite(OUT type_record) RETURNS SETOF type_record AS $$ |
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return [{'first': 1, 'second': 2}, |
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{'first': 3, 'second': 4 }] |
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$$ LANGUAGE plpythonu; |
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SELECT * FROM singleout_composite(); |
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first | second |
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-------+-------- |
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1 | 2 |
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(1 row) |
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|
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SELECT * FROM multiout_composite(); |
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first | second |
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-------+-------- |
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1 | 2 |
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3 | 4 |
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(2 rows) |
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|
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-- composite OUT parameters in functions returning RECORD not supported yet |
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CREATE FUNCTION multiout_composite(INOUT n integer, OUT type_record) AS $$ |
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return (n, (n * 2, n * 3)) |
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$$ LANGUAGE plpythonu; |
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CREATE FUNCTION multiout_table_type_setof(typ text, returnnull boolean, INOUT n integer, OUT table_record) RETURNS SETOF record AS $$ |
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if returnnull: |
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d = None |
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elif typ == 'dict': |
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d = {'first': n * 2, 'second': n * 3, 'extra': 'not important'} |
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elif typ == 'tuple': |
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d = (n * 2, n * 3) |
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elif typ == 'obj': |
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class d: pass |
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d.first = n * 2 |
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d.second = n * 3 |
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for i in range(n): |
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yield (i, d) |
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$$ LANGUAGE plpythonu; |
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SELECT * FROM multiout_composite(2); |
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n | column2 |
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---+--------- |
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2 | (4,6) |
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(1 row) |
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|
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SELECT * FROM multiout_table_type_setof('dict', 'f', 3); |
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n | column2 |
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---+--------- |
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0 | (6,9) |
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1 | (6,9) |
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2 | (6,9) |
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(3 rows) |
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|
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SELECT * FROM multiout_table_type_setof('tuple', 'f', 2); |
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n | column2 |
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---+--------- |
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0 | (4,6) |
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1 | (4,6) |
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(2 rows) |
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|
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SELECT * FROM multiout_table_type_setof('obj', 'f', 4); |
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n | column2 |
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---+--------- |
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0 | (8,12) |
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1 | (8,12) |
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2 | (8,12) |
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3 | (8,12) |
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(4 rows) |
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|
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SELECT * FROM multiout_table_type_setof('dict', 't', 3); |
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n | column2 |
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---+--------- |
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0 | |
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1 | |
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2 | |
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(3 rows) |
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|
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-- check what happens if a type changes under us |
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CREATE TABLE changing ( |
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i integer, |
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j integer |
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); |
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CREATE FUNCTION changing_test(OUT n integer, OUT changing) RETURNS SETOF record AS $$ |
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return [(1, {'i': 1, 'j': 2}), |
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(1, (3, 4))] |
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$$ LANGUAGE plpythonu; |
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SELECT * FROM changing_test(); |
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n | column2 |
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---+--------- |
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1 | (1,2) |
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1 | (3,4) |
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(2 rows) |
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|
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ALTER TABLE changing DROP COLUMN j; |
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SELECT * FROM changing_test(); |
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ERROR: length of returned sequence did not match number of columns in row |
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CONTEXT: while creating return value |
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PL/Python function "changing_test" |
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SELECT * FROM changing_test(); |
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ERROR: length of returned sequence did not match number of columns in row |
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CONTEXT: while creating return value |
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PL/Python function "changing_test" |
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ALTER TABLE changing ADD COLUMN j integer; |
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SELECT * FROM changing_test(); |
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n | column2 |
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---+--------- |
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1 | (1,2) |
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1 | (3,4) |
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(2 rows) |
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|
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-- tables of composite types (not yet implemented) |
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CREATE FUNCTION composite_types_table(OUT tab table_record[], OUT typ type_record[] ) RETURNS SETOF record AS $$ |
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yield {'tab': [['first', 1], ['second', 2]], |
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'typ': [{'first': 'third', 'second': 3}, |
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{'first': 'fourth', 'second': 4}]} |
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yield {'tab': [['first', 1], ['second', 2]], |
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'typ': [{'first': 'third', 'second': 3}, |
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{'first': 'fourth', 'second': 4}]} |
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yield {'tab': [['first', 1], ['second', 2]], |
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'typ': [{'first': 'third', 'second': 3}, |
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{'first': 'fourth', 'second': 4}]} |
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$$ LANGUAGE plpythonu; |
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SELECT * FROM composite_types_table(); |
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ERROR: PL/Python functions cannot return type table_record[] |
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DETAIL: PL/Python does not support conversion to arrays of row types. |
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CONTEXT: PL/Python function "composite_types_table" |
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-- check what happens if the output record descriptor changes |
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CREATE FUNCTION return_record(t text) RETURNS record AS $$ |
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return {'t': t, 'val': 10} |
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$$ LANGUAGE plpythonu; |
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SELECT * FROM return_record('abc') AS r(t text, val integer); |
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t | val |
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-----+----- |
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abc | 10 |
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(1 row) |
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|
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SELECT * FROM return_record('abc') AS r(t text, val bigint); |
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t | val |
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-----+----- |
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abc | 10 |
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(1 row) |
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|
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SELECT * FROM return_record('abc') AS r(t text, val integer); |
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t | val |
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-----+----- |
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abc | 10 |
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(1 row) |
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|
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SELECT * FROM return_record('abc') AS r(t varchar(30), val integer); |
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t | val |
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-----+----- |
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abc | 10 |
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(1 row) |
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|
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SELECT * FROM return_record('abc') AS r(t varchar(100), val integer); |
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t | val |
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-----+----- |
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abc | 10 |
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(1 row) |
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|
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SELECT * FROM return_record('999') AS r(val text, t integer); |
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val | t |
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-----+----- |
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10 | 999 |
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(1 row) |
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|
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CREATE FUNCTION return_record_2(t text) RETURNS record AS $$ |
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return {'v1':1,'v2':2,t:3} |
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$$ LANGUAGE plpythonu; |
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SELECT * FROM return_record_2('v3') AS (v3 int, v2 int, v1 int); |
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v3 | v2 | v1 |
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----+----+---- |
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3 | 2 | 1 |
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(1 row) |
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|
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SELECT * FROM return_record_2('v3') AS (v2 int, v3 int, v1 int); |
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v2 | v3 | v1 |
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----+----+---- |
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2 | 3 | 1 |
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(1 row) |
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|
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SELECT * FROM return_record_2('v4') AS (v1 int, v4 int, v2 int); |
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v1 | v4 | v2 |
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----+----+---- |
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1 | 3 | 2 |
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(1 row) |
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|
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SELECT * FROM return_record_2('v4') AS (v1 int, v4 int, v2 int); |
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v1 | v4 | v2 |
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----+----+---- |
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1 | 3 | 2 |
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(1 row) |
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|
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-- error |
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SELECT * FROM return_record_2('v4') AS (v1 int, v3 int, v2 int); |
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ERROR: key "v3" not found in mapping |
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HINT: To return null in a column, add the value None to the mapping with the key named after the column. |
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CONTEXT: while creating return value |
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PL/Python function "return_record_2" |
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-- works |
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SELECT * FROM return_record_2('v3') AS (v1 int, v3 int, v2 int); |
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v1 | v3 | v2 |
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----+----+---- |
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1 | 3 | 2 |
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(1 row) |
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|
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SELECT * FROM return_record_2('v3') AS (v1 int, v2 int, v3 int); |
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v1 | v2 | v3 |
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----+----+---- |
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1 | 2 | 3 |
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(1 row) |
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|
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@ -0,0 +1,168 @@ |
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CREATE FUNCTION multiout_simple(OUT i integer, OUT j integer) AS $$ |
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return (1, 2) |
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$$ LANGUAGE plpythonu; |
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|
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SELECT multiout_simple(); |
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SELECT * FROM multiout_simple(); |
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SELECT i, j + 2 FROM multiout_simple(); |
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SELECT (multiout_simple()).j + 3; |
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|
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CREATE FUNCTION multiout_simple_setof(n integer = 1, OUT integer, OUT integer) RETURNS SETOF record AS $$ |
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return [(1, 2)] * n |
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$$ LANGUAGE plpythonu; |
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|
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SELECT multiout_simple_setof(); |
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SELECT * FROM multiout_simple_setof(); |
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SELECT * FROM multiout_simple_setof(3); |
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|
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CREATE FUNCTION multiout_record_as(typ text, |
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first text, OUT first text, |
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second integer, OUT second integer, |
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retnull boolean) RETURNS record AS $$ |
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if retnull: |
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return None |
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if typ == 'dict': |
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return { 'first': first, 'second': second, 'additionalfield': 'must not cause trouble' } |
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elif typ == 'tuple': |
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return ( first, second ) |
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elif typ == 'list': |
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return [ first, second ] |
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elif typ == 'obj': |
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class type_record: pass |
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type_record.first = first |
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type_record.second = second |
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return type_record |
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$$ LANGUAGE plpythonu; |
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|
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SELECT * FROM multiout_record_as('dict', 'foo', 1, 'f'); |
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SELECT multiout_record_as('dict', 'foo', 1, 'f'); |
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SELECT *, s IS NULL AS snull FROM multiout_record_as('tuple', 'xxx', NULL, 'f') AS f(f, s); |
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SELECT *, f IS NULL AS fnull, s IS NULL AS snull FROM multiout_record_as('tuple', 'xxx', 1, 't') AS f(f, s); |
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SELECT * FROM multiout_record_as('obj', NULL, 10, 'f'); |
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|
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CREATE FUNCTION multiout_setof(n integer, |
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OUT power_of_2 integer, |
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OUT length integer) RETURNS SETOF record AS $$ |
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for i in range(n): |
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power = 2 ** i |
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length = plpy.execute("select length('%d')" % power)[0]['length'] |
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yield power, length |
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$$ LANGUAGE plpythonu; |
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|
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SELECT * FROM multiout_setof(3); |
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SELECT multiout_setof(5); |
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|
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CREATE FUNCTION multiout_return_table() RETURNS TABLE (x integer, y text) AS $$ |
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return [{'x': 4, 'y' :'four'}, |
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{'x': 7, 'y' :'seven'}, |
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{'x': 0, 'y' :'zero'}] |
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$$ LANGUAGE plpythonu; |
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|
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SELECT * FROM multiout_return_table(); |
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|
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CREATE FUNCTION multiout_array(OUT integer[], OUT text) RETURNS SETOF record AS $$ |
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yield [[1], 'a'] |
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yield [[1,2], 'b'] |
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yield [[1,2,3], None] |
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$$ LANGUAGE plpythonu; |
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|
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SELECT * FROM multiout_array(); |
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|
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CREATE FUNCTION singleout_composite(OUT type_record) AS $$ |
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return {'first': 1, 'second': 2} |
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$$ LANGUAGE plpythonu; |
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|
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CREATE FUNCTION multiout_composite(OUT type_record) RETURNS SETOF type_record AS $$ |
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return [{'first': 1, 'second': 2}, |
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{'first': 3, 'second': 4 }] |
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$$ LANGUAGE plpythonu; |
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|
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SELECT * FROM singleout_composite(); |
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SELECT * FROM multiout_composite(); |
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|
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-- composite OUT parameters in functions returning RECORD not supported yet |
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CREATE FUNCTION multiout_composite(INOUT n integer, OUT type_record) AS $$ |
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return (n, (n * 2, n * 3)) |
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$$ LANGUAGE plpythonu; |
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|
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CREATE FUNCTION multiout_table_type_setof(typ text, returnnull boolean, INOUT n integer, OUT table_record) RETURNS SETOF record AS $$ |
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if returnnull: |
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d = None |
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elif typ == 'dict': |
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d = {'first': n * 2, 'second': n * 3, 'extra': 'not important'} |
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elif typ == 'tuple': |
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d = (n * 2, n * 3) |
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elif typ == 'obj': |
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class d: pass |
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d.first = n * 2 |
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d.second = n * 3 |
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for i in range(n): |
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yield (i, d) |
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$$ LANGUAGE plpythonu; |
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|
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SELECT * FROM multiout_composite(2); |
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SELECT * FROM multiout_table_type_setof('dict', 'f', 3); |
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SELECT * FROM multiout_table_type_setof('tuple', 'f', 2); |
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SELECT * FROM multiout_table_type_setof('obj', 'f', 4); |
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SELECT * FROM multiout_table_type_setof('dict', 't', 3); |
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|
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-- check what happens if a type changes under us |
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|
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CREATE TABLE changing ( |
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i integer, |
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j integer |
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); |
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|
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CREATE FUNCTION changing_test(OUT n integer, OUT changing) RETURNS SETOF record AS $$ |
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return [(1, {'i': 1, 'j': 2}), |
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(1, (3, 4))] |
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$$ LANGUAGE plpythonu; |
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|
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SELECT * FROM changing_test(); |
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ALTER TABLE changing DROP COLUMN j; |
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SELECT * FROM changing_test(); |
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SELECT * FROM changing_test(); |
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ALTER TABLE changing ADD COLUMN j integer; |
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SELECT * FROM changing_test(); |
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|
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-- tables of composite types (not yet implemented) |
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|
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CREATE FUNCTION composite_types_table(OUT tab table_record[], OUT typ type_record[] ) RETURNS SETOF record AS $$ |
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yield {'tab': [['first', 1], ['second', 2]], |
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'typ': [{'first': 'third', 'second': 3}, |
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{'first': 'fourth', 'second': 4}]} |
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yield {'tab': [['first', 1], ['second', 2]], |
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'typ': [{'first': 'third', 'second': 3}, |
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{'first': 'fourth', 'second': 4}]} |
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yield {'tab': [['first', 1], ['second', 2]], |
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'typ': [{'first': 'third', 'second': 3}, |
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{'first': 'fourth', 'second': 4}]} |
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$$ LANGUAGE plpythonu; |
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|
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SELECT * FROM composite_types_table(); |
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|
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-- check what happens if the output record descriptor changes |
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CREATE FUNCTION return_record(t text) RETURNS record AS $$ |
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return {'t': t, 'val': 10} |
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$$ LANGUAGE plpythonu; |
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|
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SELECT * FROM return_record('abc') AS r(t text, val integer); |
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SELECT * FROM return_record('abc') AS r(t text, val bigint); |
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SELECT * FROM return_record('abc') AS r(t text, val integer); |
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SELECT * FROM return_record('abc') AS r(t varchar(30), val integer); |
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SELECT * FROM return_record('abc') AS r(t varchar(100), val integer); |
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SELECT * FROM return_record('999') AS r(val text, t integer); |
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|
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CREATE FUNCTION return_record_2(t text) RETURNS record AS $$ |
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return {'v1':1,'v2':2,t:3} |
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$$ LANGUAGE plpythonu; |
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|
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SELECT * FROM return_record_2('v3') AS (v3 int, v2 int, v1 int); |
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SELECT * FROM return_record_2('v3') AS (v2 int, v3 int, v1 int); |
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SELECT * FROM return_record_2('v4') AS (v1 int, v4 int, v2 int); |
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SELECT * FROM return_record_2('v4') AS (v1 int, v4 int, v2 int); |
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-- error |
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SELECT * FROM return_record_2('v4') AS (v1 int, v3 int, v2 int); |
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-- works |
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SELECT * FROM return_record_2('v3') AS (v1 int, v3 int, v2 int); |
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SELECT * FROM return_record_2('v3') AS (v1 int, v2 int, v3 int); |
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Reference in new issue