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Diffstat (limited to 'examples/copy_to.py')
| -rw-r--r-- | examples/copy_to.py | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/examples/copy_to.py b/examples/copy_to.py new file mode 100644 index 0000000..f4433ed --- /dev/null +++ b/examples/copy_to.py @@ -0,0 +1,105 @@ +# copy_to.py -- example about copy_to +# +# Copyright (C) 2002 Tom Jenkins <tjenkins@devis.com> +# Copyright (C) 2005 Federico Di Gregorio <fog@initd.org> +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by the +# Free Software Foundation; either version 2, or (at your option) any later +# version. +# +# This program is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTIBILITY +# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +# for more details. +# + +## put in DSN your DSN string + +DSN = 'dbname=test' + +## don't modify anything below tis line (except for experimenting) + +import sys +import os +import StringIO +import psycopg + +if len(sys.argv) > 1: + DSN = sys.argv[1] + +print "Opening connection using dns:", DSN +conn = psycopg.connect(DSN) +print "Encoding for this connection is", conn.encoding + +curs = conn.cursor() +try: + curs.execute("CREATE TABLE test_copy (fld1 text, fld2 text, fld3 int4)") +except: + conn.rollback() + curs.execute("DROP TABLE test_copy") + curs.execute("CREATE TABLE test_copy (fld1 text, fld2 text, fld3 int4)") +conn.commit() + +# demostrate copy_to functionality +data = [('Tom', 'Jenkins', '37'), + ('Madonna', None, '45'), + ('Federico', 'Di Gregorio', None)] +query = "INSERT INTO test_copy VALUES (%s, %s, %s)" +for row in data: + curs.execute(query, row) +conn.commit() + +# copy_to using defaults +io = open('copy_to.txt', 'w') +curs.copy_to(io, 'test_copy') +print "1) Copy %d records into file object using defaults: " % len (data) + \ + "sep = \\t and null = \\N" +io.close() + +rows = open('copy_to.txt', 'r').readlines() +print " File has %d rows:" % len(rows) + +for r in rows: + print " ", r, + +# copy_to using custom separator +io = open('copy_to.txt', 'w') +curs.copy_to(io, 'test_copy', ':') +print "2) Copy %d records into file object using sep = :" % len(data) +io.close() + +rows = open('copy_to.txt', 'r').readlines() +print " File has %d rows:" % len(rows) + +for r in rows: + print " ", r, + +# copy_to using custom null identifier +io = open('copy_to.txt', 'w') +curs.copy_to(io, 'test_copy', null='NULL') +print "3) Copy %d records into file object using null = NULL" % len(data) +io.close() + +rows = open('copy_to.txt', 'r').readlines() +print " File has %d rows:" % len(rows) + +for r in rows: + print " ", r, + +# copy_to using custom separator and null identifier +io = open('copy_to.txt', 'w') +curs.copy_to(io, 'test_copy', ':', 'NULL') +print "4) Copy %d records into file object using sep = : and null ) NULL" % \ + len(data) +io.close() + +rows = open('copy_to.txt', 'r').readlines() +print " File has %d rows:" % len(rows) + +for r in rows: + print " ", r, + +curs.execute("DROP TABLE test_copy") +os.unlink('copy_to.txt') +conn.commit() |
