74d9d71484
tests. Although the two are aliases of one another, it makes sense to be consistent and to use the one that the DB API prefers as well.
73 lines
2.6 KiB
Python
73 lines
2.6 KiB
Python
#------------------------------------------------------------------------------
|
|
# Copyright (c) 2016, 2018, 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.
|
|
#------------------------------------------------------------------------------
|
|
|
|
#------------------------------------------------------------------------------
|
|
# ReturnLobsAsStrings.py
|
|
# Returns all CLOB values as strings and BLOB values as bytes. The
|
|
# performance of this technique is significantly better than fetching the LOBs
|
|
# and then reading the contents of the LOBs as it avoids round-trips to the
|
|
# database. Be aware, however, that this method requires contiguous memory so
|
|
# is not usable for very large LOBs.
|
|
#
|
|
# This script requires cx_Oracle 5.0 and higher.
|
|
#------------------------------------------------------------------------------
|
|
|
|
from __future__ import print_function
|
|
|
|
import cx_Oracle
|
|
import SampleEnv
|
|
|
|
def OutputTypeHandler(cursor, name, defaultType, size, precision, scale):
|
|
if defaultType == cx_Oracle.CLOB:
|
|
return cursor.var(cx_Oracle.LONG_STRING, arraysize = cursor.arraysize)
|
|
if defaultType == cx_Oracle.BLOB:
|
|
return cursor.var(cx_Oracle.LONG_BINARY, arraysize = cursor.arraysize)
|
|
|
|
connection = cx_Oracle.connect(SampleEnv.MAIN_CONNECT_STRING)
|
|
connection.outputtypehandler = OutputTypeHandler
|
|
cursor = connection.cursor()
|
|
|
|
# add some data to the tables
|
|
print("Populating tables with data...")
|
|
cursor.execute("truncate table TestClobs")
|
|
cursor.execute("truncate table TestBlobs")
|
|
longString = ""
|
|
for i in range(10):
|
|
char = chr(ord('A') + i)
|
|
longString += char * 25000
|
|
cursor.setinputsizes(None, cx_Oracle.LONG_STRING)
|
|
cursor.execute("insert into TestClobs values (:1, :2)",
|
|
(i + 1, "STRING " + longString))
|
|
cursor.setinputsizes(None, cx_Oracle.LONG_BINARY)
|
|
cursor.execute("insert into TestBlobs values (:1, :2)",
|
|
(i + 1, longString.encode("ascii")))
|
|
connection.commit()
|
|
|
|
# fetch the data and show the results
|
|
print("CLOBS returned as strings")
|
|
cursor.execute("""
|
|
select
|
|
IntCol,
|
|
ClobCol
|
|
from TestClobs
|
|
order by IntCol""")
|
|
for intCol, value in cursor:
|
|
print("Row:", intCol, "string of length", len(value))
|
|
print()
|
|
print("BLOBS returned as bytes")
|
|
cursor.execute("""
|
|
select
|
|
IntCol,
|
|
BlobCol
|
|
from TestBlobs
|
|
order by IntCol""")
|
|
for intCol, value in cursor:
|
|
print("Row:", intCol, "string of length", value and len(value) or 0)
|
|
|