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cac7658205
This provides a mechanism for specifying conversions between SQL data types and procedural languages. As examples, there are transforms for hstore and ltree for PL/Perl and PL/Python. reviews by Pavel Stěhule and Andres Freund
46 lines
977 B
Plaintext
46 lines
977 B
Plaintext
CREATE EXTENSION plpython2u;
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CREATE EXTENSION ltree_plpython2u;
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CREATE FUNCTION test1(val ltree) RETURNS int
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LANGUAGE plpythonu
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TRANSFORM FOR TYPE ltree
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AS $$
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plpy.info(repr(val))
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return len(val)
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$$;
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SELECT test1('aa.bb.cc'::ltree);
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INFO: ['aa', 'bb', 'cc']
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CONTEXT: PL/Python function "test1"
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test1
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-------
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3
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(1 row)
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CREATE FUNCTION test1n(val ltree) RETURNS int
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LANGUAGE plpython2u
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TRANSFORM FOR TYPE ltree
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AS $$
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plpy.info(repr(val))
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return len(val)
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$$;
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SELECT test1n('aa.bb.cc'::ltree);
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INFO: ['aa', 'bb', 'cc']
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CONTEXT: PL/Python function "test1n"
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test1n
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--------
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3
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(1 row)
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CREATE FUNCTION test2() RETURNS ltree
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LANGUAGE plpythonu
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TRANSFORM FOR TYPE ltree
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AS $$
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return ['foo', 'bar', 'baz']
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$$;
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-- plpython to ltree is not yet implemented, so this will fail,
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-- because it will try to parse the Python list as an ltree input
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-- string.
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SELECT test2();
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ERROR: syntax error at position 0
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CONTEXT: while creating return value
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PL/Python function "test2"
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