Merge from trunk

[plcapi.git] / trunk / psycopg2 / examples / copy_from.py

diff --git a/trunk/psycopg2/examples/copy_from.py b/trunk/psycopg2/examples/copy_from.py
new file mode 100644 (file)
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+++ b/trunk/psycopg2/examples/copy_from.py
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+# copy_from.py -- example about copy_from 
+#
+# 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 psycopg2
+
+if len(sys.argv) > 1:
+    DSN = sys.argv[1]
+
+print "Opening connection using dns:", DSN
+conn = psycopg2.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()
+
+# copy_from with default arguments, from open file
+
+io = open('copy_from.txt', 'wr')
+data = ['Tom\tJenkins\t37\n',
+        'Madonna\t\N\t45\n',
+        'Federico\tDi Gregorio\t\N\n']
+io.writelines(data)
+io.close()
+
+io = open('copy_from.txt', 'r')
+curs.copy_from(io, 'test_copy')
+print "1) Copy %d records from file object " % len(data) + \
+      "using defaults (sep: \\t and null = \\N)"
+io.close()
+
+curs.execute("SELECT * FROM test_copy")
+rows = curs.fetchall()
+print "   Select returned %d rows" % len(rows)
+
+for r in rows:
+    print "    %s %s\t%s" % (r[0], r[1], r[2])
+curs.execute("delete from test_copy")
+conn.commit()
+
+# copy_from using custom separator, from open file
+
+io = open('copy_from.txt', 'wr')
+data = ['Tom:Jenkins:37\n',
+        'Madonna:\N:45\n',
+        'Federico:Di Gregorio:\N\n']
+io.writelines(data)
+io.close()
+
+io = open('copy_from.txt', 'r')
+curs.copy_from(io, 'test_copy', ':')
+print "2) Copy %d records from file object using sep = :" % len(data)
+io.close()
+
+curs.execute("SELECT * FROM test_copy")
+rows = curs.fetchall()
+print "   Select returned %d rows" % len(rows)
+
+for r in rows:
+    print "    %s %s\t%s" % (r[0], r[1], r[2])
+curs.execute("delete from test_copy")
+conn.commit()
+
+# copy_from using custom null identifier, from open file
+
+io = open('copy_from.txt', 'wr')
+data = ['Tom\tJenkins\t37\n',
+        'Madonna\tNULL\t45\n',
+        'Federico\tDi Gregorio\tNULL\n']
+io.writelines(data)
+io.close()
+
+io = open('copy_from.txt', 'r')
+curs.copy_from(io, 'test_copy', null='NULL')
+print "3) Copy %d records from file object using null = NULL" % len(data)
+io.close()
+
+curs.execute("SELECT * FROM test_copy")
+rows = curs.fetchall()
+print "   Select using cursor returned %d rows" % len(rows)
+
+for r in rows:
+    print "    %s %s\t%s" % (r[0], r[1], r[2])
+curs.execute("delete from test_copy")
+conn.commit()
+
+# copy_from using custom separator and null identifier
+
+io = open('copy_from.txt', 'wr')
+data = ['Tom:Jenkins:37\n', 'Madonna:NULL:45\n', 'Federico:Di Gregorio:NULL\n']
+io.writelines(data)
+io.close()
+
+io = open('copy_from.txt', 'r')
+curs.copy_from(io, 'test_copy', ':', 'NULL')
+print "4) Copy %d records from file object " % len(data) + \
+      "using sep = : and null = NULL"
+io.close()
+
+curs.execute("SELECT * FROM test_copy")
+rows = curs.fetchall()
+print "   Select using cursor returned %d rows" % len(rows)
+
+for r in rows:
+    print "    %s %s\t%s" % (r[0], r[1], r[2])
+curs.execute("delete from test_copy")
+conn.commit()
+
+# anything can be used as a file if it has .read() and .readline() methods
+
+data = StringIO.StringIO()
+data.write('\n'.join(['Tom\tJenkins\t37',
+                      'Madonna\t\N\t45',
+                      'Federico\tDi Gregorio\t\N']))
+data.seek(0)
+
+curs.copy_from(data, 'test_copy')
+print "5) Copy 3 records from StringIO object using defaults"
+
+curs.execute("SELECT * FROM test_copy")
+rows = curs.fetchall()
+print "   Select using cursor returned %d rows" % len(rows)
+
+for r in rows:
+    print "    %s %s\t%s" % (r[0], r[1], r[2])
+curs.execute("delete from test_copy")
+conn.commit()
+
+# simple error test
+
+print "6) About to raise an error"
+data = StringIO.StringIO()
+data.write('\n'.join(['Tom\tJenkins\t37',
+                      'Madonna\t\N\t45',
+                      'Federico\tDi Gregorio\taaa']))
+data.seek(0)
+
+try:
+    curs.copy_from(data, 'test_copy')
+except StandardError, err:
+    conn.rollback()
+    print "   Catched error (as expected):\n", err
+
+conn.rollback()
+
+curs.execute("DROP TABLE test_copy")
+os.unlink('copy_from.txt')
+conn.commit()
+
+
+