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PL/Python array support
Support arrays as parameters and return values of PL/Python functions.
This commit is contained in:
Peter Eisentraut
parent
a37b001b80
commit
db7386187f
@ -1,4 +1,4 @@
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<!-- $PostgreSQL: pgsql/doc/src/sgml/plpython.sgml,v 1.40 2009/03/30 16:15:43 alvherre Exp $ -->
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<!-- $PostgreSQL: pgsql/doc/src/sgml/plpython.sgml,v 1.41 2009/12/10 20:43:40 petere Exp $ -->
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<chapter id="plpython">
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<title>PL/Python - Python Procedural Language</title>
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@ -134,6 +134,43 @@ $$ LANGUAGE plpythonu;
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function is strict or not.
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</para>
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<para>
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SQL array values are passed into PL/Python as a Python list. To
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return an SQL array value out of a PL/Python function, return a
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Python sequence, for example a list or tuple:
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<programlisting>
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CREATE FUNCTION return_arr()
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RETURNS int[]
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AS $$
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return (1, 2, 3, 4, 5)
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$$ LANGUAGE plpythonu;
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SELECT return_arr();
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return_arr
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-------------
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{1,2,3,4,5}
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(1 row)
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</programlisting>
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Note that in Python, strings are sequences, which can have
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undesirable effects that might be familiar to Python programmers:
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<programlisting>
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CREATE FUNCTION return_str_arr()
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RETURNS varchar[]
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AS $$
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return "hello"
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$$ LANGUAGE plpythonu;
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SELECT return_str_arr();
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return_str_arr
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----------------
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{h,e,l,l,o}
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(1 row)
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</programlisting>
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</para>
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<para>
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Composite-type arguments are passed to the function as Python mappings. The
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element names of the mapping are the attribute names of the composite type.
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@ -477,3 +477,113 @@ CONTEXT: PL/Python function "test_type_conversion_bytea10"
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ERROR: value for domain bytea10 violates check constraint "bytea10_check"
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CONTEXT: while creating return value
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PL/Python function "test_type_conversion_bytea10"
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--
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-- Arrays
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--
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CREATE FUNCTION test_type_conversion_array_int4(x int4[]) RETURNS int4[] AS $$
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plpy.info(x, type(x))
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return x
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$$ LANGUAGE plpythonu;
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SELECT * FROM test_type_conversion_array_int4(ARRAY[0, 100]);
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INFO: ([0, 100], <type 'list'>)
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CONTEXT: PL/Python function "test_type_conversion_array_int4"
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test_type_conversion_array_int4
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---------------------------------
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{0,100}
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(1 row)
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SELECT * FROM test_type_conversion_array_int4(ARRAY[0,-100,55]);
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INFO: ([0, -100, 55], <type 'list'>)
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CONTEXT: PL/Python function "test_type_conversion_array_int4"
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test_type_conversion_array_int4
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---------------------------------
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{0,-100,55}
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(1 row)
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SELECT * FROM test_type_conversion_array_int4(ARRAY[NULL,1]);
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INFO: ([None, 1], <type 'list'>)
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CONTEXT: PL/Python function "test_type_conversion_array_int4"
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test_type_conversion_array_int4
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---------------------------------
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{NULL,1}
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(1 row)
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SELECT * FROM test_type_conversion_array_int4(ARRAY[]::integer[]);
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INFO: ([], <type 'list'>)
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CONTEXT: PL/Python function "test_type_conversion_array_int4"
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test_type_conversion_array_int4
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---------------------------------
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{}
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(1 row)
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SELECT * FROM test_type_conversion_array_int4(NULL);
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INFO: (None, <type 'NoneType'>)
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CONTEXT: PL/Python function "test_type_conversion_array_int4"
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test_type_conversion_array_int4
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---------------------------------
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(1 row)
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SELECT * FROM test_type_conversion_array_int4(ARRAY[[1,2,3],[4,5,6]]);
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ERROR: cannot convert multidimensional array to Python list
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DETAIL: PL/Python only supports one-dimensional arrays.
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CONTEXT: PL/Python function "test_type_conversion_array_int4"
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CREATE FUNCTION test_type_conversion_array_bytea(x bytea[]) RETURNS bytea[] AS $$
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plpy.info(x, type(x))
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return x
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$$ LANGUAGE plpythonu;
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SELECT * FROM test_type_conversion_array_bytea(ARRAY[E'\\xdeadbeef'::bytea, NULL]);
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INFO: (['\xde\xad\xbe\xef', None], <type 'list'>)
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CONTEXT: PL/Python function "test_type_conversion_array_bytea"
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test_type_conversion_array_bytea
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----------------------------------
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{"\\xdeadbeef",NULL}
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(1 row)
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CREATE FUNCTION test_type_conversion_array_mixed1() RETURNS text[] AS $$
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return [123, 'abc']
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$$ LANGUAGE plpythonu;
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SELECT * FROM test_type_conversion_array_mixed1();
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test_type_conversion_array_mixed1
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-----------------------------------
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{123,abc}
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(1 row)
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CREATE FUNCTION test_type_conversion_array_mixed2() RETURNS int[] AS $$
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return [123, 'abc']
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$$ LANGUAGE plpythonu;
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SELECT * FROM test_type_conversion_array_mixed2();
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ERROR: invalid input syntax for integer: "abc"
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CONTEXT: while creating return value
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PL/Python function "test_type_conversion_array_mixed2"
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CREATE FUNCTION test_type_conversion_array_record() RETURNS type_record[] AS $$
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return [None]
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$$ LANGUAGE plpythonu;
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SELECT * FROM test_type_conversion_array_record();
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ERROR: PL/Python functions cannot return type type_record[]
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DETAIL: PL/Python does not support conversion to arrays of row types.
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CREATE FUNCTION test_type_conversion_array_string() RETURNS text[] AS $$
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return 'abc'
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$$ LANGUAGE plpythonu;
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SELECT * FROM test_type_conversion_array_string();
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test_type_conversion_array_string
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-----------------------------------
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{a,b,c}
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(1 row)
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CREATE FUNCTION test_type_conversion_array_tuple() RETURNS text[] AS $$
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return ('abc', 'def')
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$$ LANGUAGE plpythonu;
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SELECT * FROM test_type_conversion_array_tuple();
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test_type_conversion_array_tuple
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----------------------------------
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{abc,def}
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(1 row)
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CREATE FUNCTION test_type_conversion_array_error() RETURNS int[] AS $$
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return 5
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$$ LANGUAGE plpythonu;
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SELECT * FROM test_type_conversion_array_error();
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ERROR: PL/Python: return value of function with array return type is not a Python sequence
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CONTEXT: while creating return value
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PL/Python function "test_type_conversion_array_error"
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@ -1,7 +1,7 @@
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/**********************************************************************
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* plpython.c - python as a procedural language for PostgreSQL
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*
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* $PostgreSQL: pgsql/src/pl/plpython/plpython.c,v 1.132 2009/11/03 11:05:02 petere Exp $
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* $PostgreSQL: pgsql/src/pl/plpython/plpython.c,v 1.133 2009/12/10 20:43:40 petere Exp $
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*
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*********************************************************************
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*/
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@ -89,6 +89,9 @@ typedef struct PLyDatumToOb
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Oid typoid; /* The OID of the type */
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Oid typioparam;
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bool typbyval;
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int16 typlen;
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char typalign;
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struct PLyDatumToOb *elm;
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} PLyDatumToOb;
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typedef struct PLyTupleToOb
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@ -120,6 +123,9 @@ typedef struct PLyObToDatum
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Oid typoid; /* The OID of the type */
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Oid typioparam;
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bool typbyval;
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int16 typlen;
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char typalign;
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struct PLyObToDatum *elm;
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} PLyObToDatum;
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typedef struct PLyObToTuple
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@ -284,6 +290,7 @@ static PyObject *PLyInt_FromInt32(PLyDatumToOb *arg, Datum d);
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static PyObject *PLyLong_FromInt64(PLyDatumToOb *arg, Datum d);
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static PyObject *PLyString_FromBytea(PLyDatumToOb *arg, Datum d);
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static PyObject *PLyString_FromDatum(PLyDatumToOb *arg, Datum d);
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static PyObject *PLyList_FromArray(PLyDatumToOb *arg, Datum d);
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static PyObject *PLyDict_FromTuple(PLyTypeInfo *, HeapTuple, TupleDesc);
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@ -293,6 +300,8 @@ static Datum PLyObject_ToBytea(PLyTypeInfo *, PLyObToDatum *,
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PyObject *);
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static Datum PLyObject_ToDatum(PLyTypeInfo *, PLyObToDatum *,
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PyObject *);
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static Datum PLySequence_ToArray(PLyTypeInfo *, PLyObToDatum *,
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PyObject *);
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static HeapTuple PLyMapping_ToTuple(PLyTypeInfo *, PyObject *);
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static HeapTuple PLySequence_ToTuple(PLyTypeInfo *, PyObject *);
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@ -1653,18 +1662,21 @@ static void
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PLy_output_datum_func2(PLyObToDatum *arg, HeapTuple typeTup)
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{
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Form_pg_type typeStruct = (Form_pg_type) GETSTRUCT(typeTup);
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Oid element_type;
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perm_fmgr_info(typeStruct->typinput, &arg->typfunc);
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arg->typoid = HeapTupleGetOid(typeTup);
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arg->typioparam = getTypeIOParam(typeTup);
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arg->typbyval = typeStruct->typbyval;
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element_type = get_element_type(arg->typoid);
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/*
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* Select a conversion function to convert Python objects to
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* PostgreSQL datums. Most data types can go through the generic
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* function.
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*/
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switch (getBaseType(arg->typoid))
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switch (getBaseType(element_type ? element_type : arg->typoid))
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{
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case BOOLOID:
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arg->func = PLyObject_ToBool;
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@ -1676,6 +1688,29 @@ PLy_output_datum_func2(PLyObToDatum *arg, HeapTuple typeTup)
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arg->func = PLyObject_ToDatum;
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break;
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}
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if (element_type)
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{
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char dummy_delim;
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Oid funcid;
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if (type_is_rowtype(element_type))
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ereport(ERROR,
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(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
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errmsg("PL/Python functions cannot return type %s",
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format_type_be(arg->typoid)),
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errdetail("PL/Python does not support conversion to arrays of row types.")));
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arg->elm = PLy_malloc0(sizeof(*arg->elm));
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arg->elm->func = arg->func;
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arg->func = PLySequence_ToArray;
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arg->elm->typoid = element_type;
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get_type_io_data(element_type, IOFunc_input,
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&arg->elm->typlen, &arg->elm->typbyval, &arg->elm->typalign, &dummy_delim,
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&arg->elm->typioparam, &funcid);
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perm_fmgr_info(funcid, &arg->elm->typfunc);
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}
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}
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static void
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@ -1691,15 +1726,17 @@ static void
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PLy_input_datum_func2(PLyDatumToOb *arg, Oid typeOid, HeapTuple typeTup)
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{
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Form_pg_type typeStruct = (Form_pg_type) GETSTRUCT(typeTup);
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Oid element_type = get_element_type(typeOid);
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/* Get the type's conversion information */
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perm_fmgr_info(typeStruct->typoutput, &arg->typfunc);
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arg->typoid = HeapTupleGetOid(typeTup);
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arg->typioparam = getTypeIOParam(typeTup);
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arg->typbyval = typeStruct->typbyval;
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arg->typlen = typeStruct->typlen;
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/* Determine which kind of Python object we will convert to */
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switch (getBaseType(typeOid))
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switch (getBaseType(element_type ? element_type : typeOid))
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{
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case BOOLOID:
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arg->func = PLyBool_FromBool;
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@ -1729,6 +1766,14 @@ PLy_input_datum_func2(PLyDatumToOb *arg, Oid typeOid, HeapTuple typeTup)
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arg->func = PLyString_FromDatum;
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break;
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}
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if (element_type)
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{
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arg->elm = PLy_malloc0(sizeof(*arg->elm));
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arg->elm->func = arg->func;
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arg->func = PLyList_FromArray;
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get_typlenbyvalalign(element_type, &arg->elm->typlen, &arg->elm->typbyval, &arg->elm->typalign);
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}
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}
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static void
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@ -1832,6 +1877,45 @@ PLyString_FromDatum(PLyDatumToOb *arg, Datum d)
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return r;
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}
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static PyObject *
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PLyList_FromArray(PLyDatumToOb *arg, Datum d)
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{
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ArrayType *array = DatumGetArrayTypeP(d);
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PyObject *list;
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int length;
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int lbound;
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int i;
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if (ARR_NDIM(array) == 0)
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return PyList_New(0);
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if (ARR_NDIM(array) != 1)
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ereport(ERROR,
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(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
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errmsg("cannot convert multidimensional array to Python list"),
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errdetail("PL/Python only supports one-dimensional arrays.")));
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length = ARR_DIMS(array)[0];
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lbound = ARR_LBOUND(array)[0];
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list = PyList_New(length);
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for (i = 0; i < length; i++)
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{
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Datum elem;
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bool isnull;
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int offset;
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offset = lbound + i;
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elem = array_ref(array, 1, &offset, arg->typlen, arg->elm->typlen, arg->elm->typbyval, arg->elm->typalign, &isnull);
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if (isnull)
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PyList_SET_ITEM(list, i, Py_None);
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else
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PyList_SET_ITEM(list, i, arg->elm->func(arg, elem));
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}
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return list;
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}
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static PyObject *
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PLyDict_FromTuple(PLyTypeInfo *info, HeapTuple tuple, TupleDesc desc)
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{
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@ -1994,6 +2078,49 @@ PLyObject_ToDatum(PLyTypeInfo *info,
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return rv;
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}
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static Datum
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PLySequence_ToArray(PLyTypeInfo *info,
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PLyObToDatum *arg,
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PyObject *plrv)
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{
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ArrayType *array;
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int i;
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Datum *elems;
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bool *nulls;
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int len;
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int lbs;
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Assert(plrv != Py_None);
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if (!PySequence_Check(plrv))
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PLy_elog(ERROR, "return value of function with array return type is not a Python sequence");
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len = PySequence_Length(plrv);
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elems = palloc(sizeof(*elems) * len);
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nulls = palloc(sizeof(*nulls) * len);
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for (i = 0; i < len; i++)
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{
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PyObject *obj = PySequence_GetItem(plrv, i);
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if (obj == Py_None)
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nulls[i] = true;
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else
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{
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nulls[i] = false;
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/* We don't support arrays of row types yet, so the first
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* argument can be NULL. */
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elems[i] = arg->elm->func(NULL, arg->elm, obj);
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}
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Py_XDECREF(obj);
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}
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lbs = 1;
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array = construct_md_array(elems, nulls, 1, &len, &lbs,
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get_element_type(arg->typoid), arg->elm->typlen, arg->elm->typbyval, arg->elm->typalign);
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return PointerGetDatum(array);
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}
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static HeapTuple
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PLyMapping_ToTuple(PLyTypeInfo *info, PyObject *mapping)
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{
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@ -204,3 +204,68 @@ SELECT * FROM test_type_conversion_bytea10('hello world', 'hello wold');
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SELECT * FROM test_type_conversion_bytea10('hello word', 'hello world');
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SELECT * FROM test_type_conversion_bytea10(null, 'hello word');
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SELECT * FROM test_type_conversion_bytea10('hello word', null);
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--
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-- Arrays
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--
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CREATE FUNCTION test_type_conversion_array_int4(x int4[]) RETURNS int4[] AS $$
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plpy.info(x, type(x))
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return x
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$$ LANGUAGE plpythonu;
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SELECT * FROM test_type_conversion_array_int4(ARRAY[0, 100]);
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SELECT * FROM test_type_conversion_array_int4(ARRAY[0,-100,55]);
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SELECT * FROM test_type_conversion_array_int4(ARRAY[NULL,1]);
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SELECT * FROM test_type_conversion_array_int4(ARRAY[]::integer[]);
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SELECT * FROM test_type_conversion_array_int4(NULL);
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SELECT * FROM test_type_conversion_array_int4(ARRAY[[1,2,3],[4,5,6]]);
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CREATE FUNCTION test_type_conversion_array_bytea(x bytea[]) RETURNS bytea[] AS $$
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plpy.info(x, type(x))
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return x
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$$ LANGUAGE plpythonu;
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SELECT * FROM test_type_conversion_array_bytea(ARRAY[E'\\xdeadbeef'::bytea, NULL]);
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CREATE FUNCTION test_type_conversion_array_mixed1() RETURNS text[] AS $$
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return [123, 'abc']
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$$ LANGUAGE plpythonu;
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SELECT * FROM test_type_conversion_array_mixed1();
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CREATE FUNCTION test_type_conversion_array_mixed2() RETURNS int[] AS $$
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return [123, 'abc']
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$$ LANGUAGE plpythonu;
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SELECT * FROM test_type_conversion_array_mixed2();
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CREATE FUNCTION test_type_conversion_array_record() RETURNS type_record[] AS $$
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return [None]
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$$ LANGUAGE plpythonu;
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SELECT * FROM test_type_conversion_array_record();
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CREATE FUNCTION test_type_conversion_array_string() RETURNS text[] AS $$
|
||||
return 'abc'
|
||||
$$ LANGUAGE plpythonu;
|
||||
|
||||
SELECT * FROM test_type_conversion_array_string();
|
||||
|
||||
CREATE FUNCTION test_type_conversion_array_tuple() RETURNS text[] AS $$
|
||||
return ('abc', 'def')
|
||||
$$ LANGUAGE plpythonu;
|
||||
|
||||
SELECT * FROM test_type_conversion_array_tuple();
|
||||
|
||||
CREATE FUNCTION test_type_conversion_array_error() RETURNS int[] AS $$
|
||||
return 5
|
||||
$$ LANGUAGE plpythonu;
|
||||
|
||||
SELECT * FROM test_type_conversion_array_error();
|
||||
|
||||
Loading…
Reference in New Issue
Block a user