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https://github.com/psycopg/psycopg2.git
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9de46e416e
Forward compatible with newer Pythons.
105 lines
2.9 KiB
Python
105 lines
2.9 KiB
Python
# copy_to.py -- example about copy_to
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#
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# Copyright (C) 2002 Tom Jenkins <tjenkins@devis.com>
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# Copyright (C) 2005 Federico Di Gregorio <fog@initd.org>
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#
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# psycopg2 is free software: you can redistribute it and/or modify it
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# under the terms of the GNU Lesser General Public License as published
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# by the Free Software Foundation, either version 3 of the License, or
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# (at your option) any later version.
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#
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# psycopg2 is distributed in the hope that it will be useful, but WITHOUT
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# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
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# License for more details.
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## put in DSN your DSN string
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DSN = 'dbname=test'
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## don't modify anything below this line (except for experimenting)
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from __future__ import print_function
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import sys
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import os
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import StringIO
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import psycopg2
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if len(sys.argv) > 1:
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DSN = sys.argv[1]
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print("Opening connection using dsn:", DSN)
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conn = psycopg2.connect(DSN)
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print("Encoding for this connection is", conn.encoding)
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curs = conn.cursor()
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try:
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curs.execute("CREATE TABLE test_copy (fld1 text, fld2 text, fld3 int4)")
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except:
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conn.rollback()
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curs.execute("DROP TABLE test_copy")
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curs.execute("CREATE TABLE test_copy (fld1 text, fld2 text, fld3 int4)")
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conn.commit()
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# demostrate copy_to functionality
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data = [('Tom', 'Jenkins', '37'),
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('Madonna', None, '45'),
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('Federico', 'Di Gregorio', None)]
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query = "INSERT INTO test_copy VALUES (%s, %s, %s)"
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curs.executemany(query, data)
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conn.commit()
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# copy_to using defaults
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io = open('copy_to.txt', 'w')
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curs.copy_to(io, 'test_copy')
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print("1) Copy %d records into file object using defaults: " % len (data) + \
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"sep = \\t and null = \\N")
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io.close()
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rows = open('copy_to.txt', 'r').readlines()
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print(" File has %d rows:" % len(rows))
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for r in rows:
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print(" ", r, end=' ')
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# copy_to using custom separator
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io = open('copy_to.txt', 'w')
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curs.copy_to(io, 'test_copy', ':')
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print("2) Copy %d records into file object using sep = :" % len(data))
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io.close()
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rows = open('copy_to.txt', 'r').readlines()
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print(" File has %d rows:" % len(rows))
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for r in rows:
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print(" ", r, end=' ')
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# copy_to using custom null identifier
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io = open('copy_to.txt', 'w')
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curs.copy_to(io, 'test_copy', null='NULL')
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print("3) Copy %d records into file object using null = NULL" % len(data))
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io.close()
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rows = open('copy_to.txt', 'r').readlines()
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print(" File has %d rows:" % len(rows))
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for r in rows:
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print(" ", r, end=' ')
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# copy_to using custom separator and null identifier
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io = open('copy_to.txt', 'w')
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curs.copy_to(io, 'test_copy', ':', 'NULL')
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print("4) Copy %d records into file object using sep = : and null ) NULL" % \
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len(data))
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io.close()
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rows = open('copy_to.txt', 'r').readlines()
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print(" File has %d rows:" % len(rows))
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for r in rows:
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print(" ", r, end=' ')
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curs.execute("DROP TABLE test_copy")
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os.unlink('copy_to.txt')
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conn.commit()
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