Here's the first cut at my solution. The example code is at the
bottom. It takes a table of tuples and uses COPY table FROM stdin in
to add them to a new table and then uses a simple INSERT statement to
append the new rows into the existing author table. The function
parse_connection_args is just the beginning of the pgdb.connect()
-- Chris
----- Example --------------------------------------------------------------
#! /usr/bin/env python
import pg, pgdb
class PreConnectedDB(pg.DB):
"""A way to get a pg.DB object around a connection established from the
pgdb.connect() method."""
def __init__(self, cnx):
self.db = cnx
self.dbname = self.db.db
self.__attnames = {}
self.__pkeys = {}
## self.__args = args, kw
self.debug = None # For debugging scripts, this can be set
# * to a string format specification (e.g. in a
CGI set to "%s<BR>"),
# * to a function which takes a string argument or
# * to a file object to write debug statements to.
def close(self):
"""Don't allow the subconnection to close the connection to the
database."""
raise pg.InternalError, "Subconnection is not allowed to close the
database."
class pgdbCnxWithClassicDb(pgdb.pgdbCnx):
def __init__(self, cnx):
self.classicDb = cnx
pgdb.pgdbCnx.__init__(self, cnx)
def get_classic_db(self):
print self.__dict__.keys()
return PreConnectedDB(self.classicDb)
def parse_connection_args(dsn = None,
user = None, password = None,
host = None, database = None):
# first get params from DSN
dbport = -1
dbhost = ""
dbbase = ""
dbuser = ""
dbpasswd = ""
dbopt = ""
dbtty = ""
try:
params = string.split(dsn, ":")
dbhost = params[0]
dbbase = params[1]
dbuser = params[2]
dbpasswd = params[3]
dbopt = params[4]
dbtty = params[5]
except:
pass
# override if necessary
if user != None:
dbuser = user
if password != None:
dbpasswd = password
if database != None:
dbbase = database
if host != None:
try:
params = string.split(host, ":")
dbhost = params[0]
dbport = int(params[1])
except:
pass
# empty host is localhost
if dbhost == "":
dbhost = None
if dbuser == "":
dbuser = None
return (dbbase, dbhost, dbport, dbopt, dbtty, dbuser, dbpasswd)
def connect(*args, **kwargs):
dbbase, dbhost, dbport, dbopt, dbtty, dbuser, dbpasswd =
parse_connection_args(*args, **kwargs)
# open the connection
cnx = pg.connect(dbbase, dbhost, dbport, dbopt, dbtty, dbuser, dbpasswd)
return pgdbCnxWithClassicDb(cnx)
if __name__ == '__main__':
data = ( ('ernest', '[EMAIL PROTECTED]'),
('richard', '[EMAIL PROTECTED]'),
('gwright', '[EMAIL PROTECTED]'),
('lniven', '[EMAIL PROTECTED]'),
('jerry', '[EMAIL PROTECTED]'))
dbiDb = connect(database = 'message_board')
c = dbiDb.cursor()
c.execute("CREATE TEMPORARY TABLE new_author AS "
+ "SELECT author_nickname, author_email FROM author LIMIT 0")
classicDb = dbiDb.get_classic_db()
classicDb.query('COPY new_author FROM stdin')
for row in data:
l = ("\t".join(row)) + "\n"
classicDb.putline(l)
classicDb.putline('\\.\n')
classicDb.endcopy()
del classicDb
c.execute("INSERT INTO author (author_nickname, author_email) "
+"SELECT author_nickname, author_email FROM new_author")
dbiDb.commit()
dbiDb.close()
----- End example ----------------------------------------------------------
--
Chris Hilton chris-at-vindaloo-dot-com
------------------------------------------------------------------------
"All I was doing was trying to get home from work!"
-- Rosa Parks
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