pgmodule.c

关系型数据库 Postgresql 6.5.2

			char	   *s = PQgetvalue(self->last_result, i, j);
			char		cashbuf[64];

			switch (typ[j])
			{
				case 1:
					val = PyInt_FromLong(strtol(s, NULL, 10));
					break;

				case 2:
					val = PyFloat_FromDouble(strtod(s, NULL));
					break;

				case 3: /* get rid of the '$' and commas */
					if (*s == '$')		/* there's talk of getting rid of
										 * it */
						s++;

					if ((s[0] == '-' || s[0] == '(') && s[1] == '$')
						*(++s) = '-';

					for (k = 0; *s; s++)
						if (*s != ',')
							cashbuf[k++] = *s;

					cashbuf[k] = 0;
					val = PyFloat_FromDouble(strtod(cashbuf, NULL));
					break;

				default:
					val = PyString_FromString(s);
					break;
			}

			PyDict_SetItemString(dict, PQfname(self->last_result, j), val);
			Py_XDECREF(val);
		}

		PyList_Append(reslist, dict);
		Py_XDECREF(dict);
	}

	free(typ);

	/* returns list */
	return reslist;
}

/* gets asynchronous notify */
static char pg_getnotify__doc__[] =
"getnotify() -- get database notify for this connection.";

static PyObject *
pg_getnotify(pgobject * self, PyObject * args)
{
	PGnotify   *notify;
	PGresult   *result;
	PyObject   *notify_result,
			   *temp;

	if (!self->cnx)
	{
		PyErr_SetString(PyExc_TypeError, "Connection is not valid");
		return NULL;
	}

	/* checks args */
	if (!PyArg_ParseTuple(args, ""))
	{
		PyErr_SetString(PyExc_SyntaxError,
						"method getnotify() takes no parameters.");
		return NULL;
	}

	/* gets notify and builds result */

	/*
	 * notifies only come back as result of a query, so I send an empty
	 * query
	 */
	result = PQexec(self->cnx, " ");

	if ((notify = PQnotifies(self->cnx)) != NULL)
	{
		notify_result = PyTuple_New(2);
		temp = PyString_FromString(notify->relname);
		PyTuple_SetItem(notify_result, 0, temp);
		temp = PyInt_FromLong(notify->be_pid);
		PyTuple_SetItem(notify_result, 1, temp);
		free(notify);
	}
	else
	{
		Py_INCREF(Py_None);
		notify_result = Py_None;
	}

	PQclear(result);

	/* returns result */
	return notify_result;
}

/* database query */
static char pg_query__doc__[] =
"query() -- creates a new query object for this connection.";

static PyObject *
pg_query(pgobject * self, PyObject * args)
{
	char	   *query;
	PGresult   *result;
	pgqueryobject *npgobj;
	int			status;

	if (!self->cnx)
	{
		PyErr_SetString(PyExc_TypeError, "Connection is not valid");
		return NULL;
	}

	/* get query args */
	if (!PyArg_ParseTuple(args, "s", &query))
	{
		PyErr_SetString(PyExc_TypeError, "query(sql), with sql (string).");
		return NULL;
	}

	/* gets result */
	result = PQexec(self->cnx, query);

	/* checks result validity */
	if (!result)
	{
		PyErr_SetString(PyExc_ValueError, PQerrorMessage(self->cnx));
		return NULL;
	}

	/* checks result status */
	if ((status = PQresultStatus(result)) != PGRES_TUPLES_OK)
	{
		const char *str;

		PQclear(result);

		switch (status)
		{
			case PGRES_EMPTY_QUERY:
				PyErr_SetString(PyExc_ValueError, "empty query.");
				break;
			case PGRES_BAD_RESPONSE:
			case PGRES_FATAL_ERROR:
			case PGRES_NONFATAL_ERROR:
				PyErr_SetString(PGError, PQerrorMessage(self->cnx));
				break;
			case PGRES_COMMAND_OK:		/* could be an INSERT */
				if (*(str = PQoidStatus(result)) == 0)	/* nope */
				{
					Py_INCREF(Py_None);
					return Py_None;
				}

				/* otherwise, return the oid */
				return PyInt_FromLong(strtol(str, NULL, 10));

			case PGRES_COPY_OUT:		/* no data will be received */
			case PGRES_COPY_IN:
				Py_INCREF(Py_None);
				return Py_None;
			default:
				PyErr_SetString(PGError, "internal error: "
								"unknown result status.");
				break;
		}

		return NULL;			/* error detected on query */
	}

	if ((npgobj = PyObject_NEW(pgqueryobject, &PgQueryType)) == NULL)
		return NULL;

	/* stores result and returns object */
	npgobj->last_result = result;
	return (PyObject *) npgobj;
}

#ifdef DIRECT_ACCESS
static char pg_putline__doc__[] =
"putline() -- sends a line directly to the backend";

/* direct acces function : putline */
static PyObject *
pg_putline(pgobject * self, PyObject * args)
{
	char	   *line;

	if (!self->cnx)
	{
		PyErr_SetString(PyExc_TypeError, "Connection is not valid");
		return NULL;
	}

	/* reads args */
	if (!PyArg_ParseTuple(args, "s", &line))
	{
		PyErr_SetString(PyExc_TypeError, "putline(line), with line (string).");
		return NULL;
	}

	/* sends line to backend */
	PQputline(self->cnx, line);
	Py_INCREF(Py_None);
	return Py_None;
}

/* direct access function : getline */
static char pg_getline__doc__[] =
"getline() -- gets a line directly from the backend.";

static PyObject *
pg_getline(pgobject * self, PyObject * args)
{
	char		line[MAX_BUFFER_SIZE];
	PyObject   *str = NULL;		/* GCC */
	int			ret;

	if (!self->cnx)
	{
		PyErr_SetString(PyExc_TypeError, "Connection is not valid");
		return NULL;
	}

	/* checks args */
	if (!PyArg_ParseTuple(args, ""))
	{
		PyErr_SetString(PyExc_SyntaxError,
						"method getline() takes no parameters.");
		return NULL;
	}

	/* gets line */
	switch (PQgetline(self->cnx, line, MAX_BUFFER_SIZE))
	{
		case 0:
			str = PyString_FromString(line);
			break;
		case 1:
			PyErr_SetString(PyExc_MemoryError, "buffer overflow");
			str = NULL;
			break;
		case EOF:
			Py_INCREF(Py_None);
			str = Py_None;
			break;
	}

	return str;
}

/* direct access function : end copy */
static char pg_endcopy__doc__[] =
"endcopy() -- synchronizes client and server";

static PyObject *
pg_endcopy(pgobject * self, PyObject * args)
{
	if (!self->cnx)
	{
		PyErr_SetString(PyExc_TypeError, "Connection is not valid");
		return NULL;
	}

	/* checks args */
	if (!PyArg_ParseTuple(args, ""))
	{
		PyErr_SetString(PyExc_SyntaxError,
						"method endcopy() takes no parameters.");
		return NULL;
	}

	/* ends direct copy */
	PQendcopy(self->cnx);
	Py_INCREF(Py_None);
	return Py_None;
}

#endif	 /* DIRECT_ACCESS */


static PyObject *
pgquery_print(pgqueryobject * self, FILE *fp, int flags)
{
	PQprintOpt	op;

	memset(&op, 0, sizeof(op));
	op.align = 1;
	op.header = 1;
	op.fieldSep = "|";
	op.pager = 1;
	PQprint(fp, self->last_result, &op);
	return 0;
}

/* insert table */
static char pg_inserttable__doc__[] =
"inserttable(string, list) -- insert list in table. The fields in the list "
"must be in the same order as in the table.";

static PyObject *
pg_inserttable(pgobject * self, PyObject * args)
{
	PGresult   *result;
	char	   *table,
			   *buffer,
			   *temp;
	char		temp_buffer[256];
	PyObject   *list,
			   *sublist,
			   *item;
	PyObject   *(*getitem) (PyObject *, int);
	PyObject   *(*getsubitem) (PyObject *, int);
	int			i,
				j;

	if (!self->cnx)
	{
		PyErr_SetString(PyExc_TypeError, "Connection is not valid");
		return NULL;
	}

	/* gets arguments */
	if (!PyArg_ParseTuple(args, "sO:filter", &table, &list))
	{
		PyErr_SetString(PyExc_TypeError,
					  "tableinsert(table, content), with table (string) "
						"and content (list).");
		return NULL;
	}

	/* checks list type */
	if (PyTuple_Check(list))
		getitem = PyTuple_GetItem;
	else if (PyList_Check(list))
		getitem = PyList_GetItem;
	else
	{
		PyErr_SetString(PyExc_TypeError,
						"second arg must be some kind of array.");
		return NULL;
	}

	/* checks sublists type */
	for (i = 0; (sublist = getitem(list, i)) != NULL; i++)
	{
		if (!PyTuple_Check(sublist) && !PyList_Check(sublist))
		{
			PyErr_SetString(PyExc_TypeError,
						 "second arg must contain some kind of arrays.");
			return NULL;
		}
	}

	/* allocate buffer */
	if (!(buffer = malloc(MAX_BUFFER_SIZE)))
	{
		PyErr_SetString(PyExc_MemoryError, "can't allocate insert buffer.");
		return NULL;
	}

	/* starts query */
	sprintf(buffer, "copy %s from stdin", table);

	if (!(result = PQexec(self->cnx, buffer)))
	{
		free(buffer);
		PyErr_SetString(PyExc_ValueError, PQerrorMessage(self->cnx));
		return NULL;
	}

	PQclear(result);

	/* feeds table */
	for (i = 0; (sublist = getitem(list, i)) != NULL; i++)
	{
		if (PyTuple_Check(sublist))
			getsubitem = PyTuple_GetItem;
		else
			getsubitem = PyList_GetItem;

		/* builds insert line */
		buffer[0] = 0;

		for (j = 0; (item = getsubitem(sublist, j)) != NULL; j++)
		{
			/* converts item to string */
			if (PyString_Check(item))
				PyArg_ParseTuple(item, "s", &temp);
			else if (PyInt_Check(item))
			{
				int			k;

				PyArg_ParseTuple(item, "i", &k);
				sprintf(temp_buffer, "%d", k);
				temp = temp_buffer;
			}
			else if (PyLong_Check(item))
			{
				long		k;

				PyArg_ParseTuple(item, "l", &k);
				sprintf(temp_buffer, "%ld", k);
				temp = temp_buffer;
			}
			else if (PyFloat_Check(item))
			{
				double		k;

				PyArg_ParseTuple(item, "d", &k);
				sprintf(temp_buffer, "%g", k);
				temp = temp_buffer;
			}
			else
			{
				free(buffer);
				PyErr_SetString(PyExc_ValueError,
								"items must be strings, integers, "
								"longs or double (real).");
				return NULL;
			}

			/* concats buffer */
			if (strlen(buffer))
				strncat(buffer, "\t", MAX_BUFFER_SIZE - strlen(buffer));

			fprintf(stderr, "Buffer: '%s', Temp: '%s'\n", buffer, temp);
			strncat(buffer, temp, MAX_BUFFER_SIZE - strlen(buffer));
		}

		strncat(buffer, "\n", MAX_BUFFER_SIZE - strlen(buffer));

		/* sends data */
		PQputline(self->cnx, buffer);
	}

	/* ends query */
	PQputline(self->cnx, ".\n");
	PQendcopy(self->cnx);
	free(buffer);

	/* no error : returns nothing */
	Py_INCREF(Py_None);
	return Py_None;
}

/* creates large object */
static char pg_locreate__doc__[] =
"locreate() -- creates a new large object in the database.";

static PyObject *
pg_locreate(pgobject * self, PyObject * args)
{
	int			mode;
	Oid			lo_oid;

	/* checks validity */
	if (!check_cnx_obj(self))
		return NULL;

	/* gets arguments */
	if (!PyArg_ParseTuple(args, "i", &mode))
	{
		PyErr_SetString(PyExc_TypeError,
						"locreate(mode), with mode (integer).");
		return NULL;
	}

	/* creates large object */
	lo_oid = lo_creat(self->cnx, mode);
	if (lo_oid == 0)
	{
		PyErr_SetString(PGError, "can't create large object.");
		return NULL;
	}

	return (PyObject *) pglarge_new(self, lo_oid);
}

/* init from already known oid */
static char pg_getlo__doc__[] =
"getlo(long) -- create a large object instance for the specified oid.";

static PyObject *
pg_getlo(pgobject * self, PyObject * args)
{
	int			lo_oid;

	/* checks validity */
	if (!check_cnx_obj(self))
		return NULL;

	/* gets arguments */
	if (!PyArg_ParseTuple(args, "i", &lo_oid))
	{
		PyErr_SetString(PyExc_TypeError, "loopen(oid), with oid (integer).");
		return NULL;
	}

	if (!lo_oid)
	{
		PyErr_SetString(PyExc_ValueError, "the object oid can't be null.");
		return NULL;
	}

	/* creates object */
	return (PyObject *) pglarge_new(self, lo_oid);
}

/* import unix file */
static char pg_loimport__doc__[] =
"loimport(string) -- create a new large object from specified file.";

static PyObject *
pg_loimport(pgobject * self, PyObject * args)
{
	char	   *name;
	Oid			lo_oid;

	/* checks validity */
	if (!check_cnx_obj(self))
		return NULL;

	/* gets arguments */
	if (!PyArg_ParseTuple(args, "s", &name))
	{
		PyErr_SetString(PyExc_TypeError, "loimport(name), with name (string).");
		return NULL;
	}

	/* imports file and checks result */
	lo_oid = lo_import(self->cnx, name);
	if (lo_oid == 0)
	{
		PyErr_SetString(PGError, "can't create large object.");
		return NULL;
	}

	return (PyObject *) pglarge_new(self, lo_oid);
}


/* connection object methods */
static struct PyMethodDef pgobj_methods[] = {
	{"query", (PyCFunction) pg_query, 1, pg_query__doc__},
	{"reset", (PyCFunction) pg_reset, 1, pg_reset__doc__},
	{"close", (PyCFunction) pg_close, 1, pg_close__doc__},
	{"fileno", (PyCFunction) pg_fileno, 1, pg_fileno__doc__},
	{"getnotify", (PyCFunction) pg_getnotify, 1, pg_getnotify__doc__},
	{"inserttable", (PyCFunction) pg_inserttable, 1, pg_inserttable__doc__},

#ifdef DIRECT_ACCESS
	{"putline", (PyCFunction) pg_putline, 1, pg_putline__doc__},
	{"getline", (PyCFunction) pg_getline, 1, pg_getline__doc__},
	{"endcopy", (PyCFunction) pg_endcopy, 1, pg_endcopy__doc__},
#endif	 /* DIRECT_ACCESS */

#ifdef LARGE_OBJECTS
	{"locreate", (PyCFunction) pg_locreate, 1, pg_locreate__doc__},
	{"getlo", (PyCFunction) pg_getlo, 1, pg_getlo__doc__},
	{"loimport", (PyCFunction) pg_loimport, 1, pg_loimport__doc__},
#endif	 /* LARGE_OBJECTS */

	{NULL, NULL}				/* sentinel */
};

/* get attribute */