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66 lines
2.1 KiB
Python
66 lines
2.1 KiB
Python
# typecast.py - example of per-cursor and per-connection typecasters.
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#
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# Copyright (C) 2001-2010 Federico Di Gregorio <fog@debian.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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class SimpleQuoter(object):
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def sqlquote(x=None):
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return "'bar'"
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import sys
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import psycopg2
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import psycopg2.extensions
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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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curs.execute("SELECT 'text'::text AS foo")
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textoid = curs.description[0][1]
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print("Oid for the text datatype is", textoid)
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def castA(s, curs):
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if s is not None: return "(A) " + s
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TYPEA = psycopg2.extensions.new_type((textoid,), "TYPEA", castA)
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def castB(s, curs):
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if s is not None: return "(B) " + s
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TYPEB = psycopg2.extensions.new_type((textoid,), "TYPEB", castB)
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curs = conn.cursor()
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curs.execute("SELECT 'some text.'::text AS foo")
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print("Some text from plain connection:", curs.fetchone()[0])
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psycopg2.extensions.register_type(TYPEA, conn)
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curs = conn.cursor()
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curs.execute("SELECT 'some text.'::text AS foo")
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print("Some text from connection with typecaster:", curs.fetchone()[0])
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curs = conn.cursor()
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psycopg2.extensions.register_type(TYPEB, curs)
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curs.execute("SELECT 'some text.'::text AS foo")
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print("Some text from cursor with typecaster:", curs.fetchone()[0])
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curs = conn.cursor()
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curs.execute("SELECT 'some text.'::text AS foo")
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print("Some text from connection with typecaster again:", curs.fetchone()[0])
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