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Hook up the plpython result-object nrows and status methods correctly.
Adjust documentation to match current reality.
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@ -1,4 +1,4 @@
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<!-- $PostgreSQL: pgsql/doc/src/sgml/plpython.sgml,v 1.24 2004/09/13 20:05:18 tgl Exp $ -->
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<!-- $PostgreSQL: pgsql/doc/src/sgml/plpython.sgml,v 1.25 2004/12/17 02:14:44 tgl Exp $ -->
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<chapter id="plpython">
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<title>PL/Python - Python Procedural Language</title>
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@ -46,7 +46,8 @@
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<title>PL/Python Functions</title>
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<para>
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The Python code you write gets transformed into a Python function. E.g.,
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The Python code you write gets transformed into a Python function.
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For example,
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<programlisting>
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CREATE FUNCTION myfunc(text) RETURNS text
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AS 'return args[0]'
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@ -60,13 +61,14 @@ def __plpython_procedure_myfunc_23456():
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return args[0]
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</programlisting>
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assuming that 23456 is the OID of the function.
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assuming that 23456 is the OID assigned to the function by
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<productname>PostgreSQL</productname>.
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</para>
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<para>
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If you do not provide a return value, Python returns the default
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<symbol>None</symbol>. The language module translates Python's
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<symbol>None</symbol> into the SQL null
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<symbol>None</symbol>. <application>PL/Python</application> translates
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Python's <symbol>None</symbol> into the SQL null
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value.<indexterm><primary>null value</><secondary
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sortas="PL/Python">in PL/Python</></indexterm>
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</para>
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@ -108,7 +110,7 @@ def __plpython_procedure_myfunc_23456():
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</indexterm>
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<para>
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When a function is used in a trigger, the dictionary
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When a function is used as a trigger, the dictionary
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<literal>TD</literal> contains trigger-related values. The trigger
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rows are in <literal>TD["new"]</> and/or <literal>TD["old"]</>
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depending on the trigger event. <literal>TD["event"]</> contains
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@ -120,9 +122,9 @@ def __plpython_procedure_myfunc_23456():
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<literal>STATEMENT</>, and <literal>UNKNOWN</>.
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<literal>TD["name"]</> contains the trigger name, and
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<literal>TD["relid"]</> contains the OID of the table on
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which the trigger occurred. If the trigger was called with
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arguments they are available in <literal>TD["args"][0]</> to
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<literal>TD["args"][(n-1)]</>.
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which the trigger occurred. If the <command>CREATE TRIGGER</> command
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included arguments, they are available in <literal>TD["args"][0]</> to
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<literal>TD["args"][(<replaceable>n</>-1)]</>.
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</para>
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<para>
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@ -143,23 +145,23 @@ def __plpython_procedure_myfunc_23456():
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this module are available to you in the Python code as
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<literal>plpy.<replaceable>foo</replaceable></literal>. At present
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<literal>plpy</literal> implements the functions
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<literal>plpy.debug("msg")</literal>,
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<literal>plpy.log("msg")</literal>,
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<literal>plpy.info("msg")</literal>,
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<literal>plpy.notice("msg")</literal>,
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<literal>plpy.warning("msg")</literal>,
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<literal>plpy.error("msg")</literal>, and
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<literal>plpy.fatal("msg")</literal>. They are mostly equivalent
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to calling <literal>elog(<replaceable>LEVEL</>, "msg")</literal>
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<literal>plpy.debug(<replaceable>msg</>)</literal>,
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<literal>plpy.log(<replaceable>msg</>)</literal>,
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<literal>plpy.info(<replaceable>msg</>)</literal>,
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<literal>plpy.notice(<replaceable>msg</>)</literal>,
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<literal>plpy.warning(<replaceable>msg</>)</literal>,
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<literal>plpy.error(<replaceable>msg</>)</literal>, and
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<literal>plpy.fatal(<replaceable>msg</>)</literal>.
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These are mostly equivalent to calling
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<literal>elog(<replaceable>level</>, <replaceable>msg</>)</literal>
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from C code.<indexterm><primary>elog</><secondary>in
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PL/Python</></indexterm> <function>plpy.error</function> and
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<function>plpy.fatal</function> actually raise a Python exception
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which, if uncaught, causes the PL/Python module to call
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<literal>elog(ERROR, msg)</literal> when the function handler
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returns from the Python interpreter. Long-jumping out of the
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Python interpreter is probably not good. <literal>raise
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plpy.ERROR("msg")</literal> and <literal>raise
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plpy.FATAL("msg")</literal> are equivalent to calling
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returns from the Python interpreter. <literal>raise
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plpy.ERROR(<replaceable>msg</>)</literal> and <literal>raise
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plpy.FATAL(<replaceable>msg</>)</literal> are equivalent to calling
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<function>plpy.error</function> and
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<function>plpy.fatal</function>, respectively.
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</para>
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@ -210,17 +212,6 @@ rv = plpy.execute(plan, [ "name" ], 5)
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The third argument is the limit and is optional.
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</para>
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<para>
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In the current version, any database error encountered while
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running a <application>PL/Python</application> function will result
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in the immediate termination of that function by the server; it is
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not possible to trap error conditions using Python <literal>try
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... catch</literal> constructs. For example, a syntax error in an
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SQL statement passed to the <literal>plpy.execute</literal> call
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will terminate the function. This behavior may be changed in a
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future release.
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</para>
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<para>
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When you prepare a plan using the PL/Python module it is
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automatically saved. Read the SPI documentation (<xref
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