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#------------------------------------------------------------------------------

# type_handlers.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.

# This script requires cx_Oracle 5.0 and higher.

#------------------------------------------------------------------------------

import datetime

import cx_Oracle as oracledb

import sample_env

con = oracledb.connect(sample_env.get_main_connect_string())

obj_type = con.gettype("UDT_BUILDING")

class Building:

def __init__(self, building_id, description, num_floors, date_built):

self.building_id = building_id

self.description = description

self.num_floors = num_floors

self.date_built = date_built

def __repr__(self):

return "<Building %s: %s>" % (self.building_id, self.description)

def building_in_converter(value):

obj = obj_type.newobject()

obj.BUILDINGID = value.building_id

obj.DESCRIPTION = value.description

obj.NUMFLOORS = value.num_floors

obj.DATEBUILT = value.date_built

return obj

def building_out_converter(obj):

return Building(int(obj.BUILDINGID), obj.DESCRIPTION, int(obj.NUMFLOORS),

obj.DATEBUILT)

def input_type_handler(cursor, value, num_elements):

if isinstance(value, Building):

return cursor.var(obj_type, arraysize=num_elements,

inconverter=building_in_converter)

def output_type_handler(cursor, name, default_type, size, precision, scale):

if default_type == oracledb.OBJECT:

return cursor.var(obj_type, arraysize=cursor.arraysize,

outconverter=building_out_converter)

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 = input_type_handler

for building in buildings:

try:

cur.execute("insert into TestBuildings values (:1, :2)",

(building.building_id, building))

except oracledb.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 = output_type_handler

print("WITH OUTPUT TYPE HANDLER:")

for row in cur.execute("select * from TestBuildings order by BuildingId"):

print(row)

print()

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