python-cx_Oracle/samples/TypeHandlers.py

93 lines
3.1 KiB
Python

#------------------------------------------------------------------------------
# Copyright 2016, 2017, Oracle and/or its affiliates. All rights reserved.
#
# Portions Copyright 2007-2015, Anthony Tuininga. All rights reserved.
#
# Portions Copyright 2001-2007, Computronix (Canada) Ltd., Edmonton, Alberta,
# Canada. All rights reserved.
#------------------------------------------------------------------------------
#------------------------------------------------------------------------------
# TypeHandlers.py
# This script demonstrates the use of input and output type handlers as well
# as variable input and output converters. These methods can be used to extend
# cx_Oracle in many ways. This script demonstrates the binding and querying of
# SQL objects as Python objects.
#------------------------------------------------------------------------------
from __future__ import print_function
import cx_Oracle
import datetime
con = cx_Oracle.connect("cx_Oracle/dev@localhost/orcl")
objType = con.gettype("UDT_BUILDING")
class Building(object):
def __init__(self, buildingId, description, numFloors, dateBuilt):
self.buildingId = buildingId
self.description = description
self.numFloors = numFloors
self.dateBuilt = dateBuilt
def __repr__(self):
return "<Building %s: %s>" % (self.buildingId, self.description)
def BuildingInConverter(value):
obj = objType.newobject()
obj.BUILDINGID = value.buildingId
obj.DESCRIPTION = value.description
obj.NUMFLOORS = value.numFloors
obj.DATEBUILT = value.dateBuilt
return obj
def BuildingOutConverter(obj):
return Building(int(obj.BUILDINGID), obj.DESCRIPTION, int(obj.NUMFLOORS),
obj.DATEBUILT)
def InputTypeHandler(cursor, value, numElements):
if isinstance(value, Building):
return cursor.var(cx_Oracle.OBJECT, arraysize = numElements,
inconverter = BuildingInConverter, typename = objType.name)
def OutputTypeHandler(cursor, name, defaultType, size, precision, scale):
if defaultType == cx_Oracle.OBJECT:
return cursor.var(cx_Oracle.OBJECT, arraysize = cursor.arraysize,
outconverter = BuildingOutConverter, typename = objType.name)
buildings = [
Building(1, "The First Building", 5, datetime.date(2007, 5, 18)),
Building(2, "The Second Building", 87, datetime.date(2010, 2, 7)),
Building(3, "The Third Building", 12, datetime.date(2005, 6, 19)),
]
cur = con.cursor()
cur.inputtypehandler = InputTypeHandler
for building in buildings:
try:
cur.execute("insert into TestBuildings values (:1, :2)",
(building.buildingId, building))
except cx_Oracle.DatabaseError as e:
error, = e.args
print("CONTEXT:", error.context)
print("MESSAGE:", error.message)
raise
print("NO OUTPUT TYPE HANDLER:")
for row in cur.execute("select * from TestBuildings order by BuildingId"):
print(row)
print()
cur = con.cursor()
cur.outputtypehandler = OutputTypeHandler
print("WITH OUTPUT TYPE HANDLER:")
for row in cur.execute("select * from TestBuildings order by BuildingId"):
print(row)
print()