pgworksheet_yvesf/pgw/DBConnection.py

   1 # -*- coding: latin-1; -*-
   2 #
   3 # PgWorksheet - PostgreSQL Front End
   4 # http://pgworksheet.projects.postgresql.org/
   5 #
   6 # Copyright © 2004-2005 Henri Michelon & CML http://www.e-cml.org/
   7 #
   8 # This program is free software; you can redistribute it and/or
   9 # modify it under the terms of the GNU General Public License
  10 # as published by the Free Software Foundation; either version 2
  11 # of the License, or (at your option) any later version.
  12 #
  13 # This program is distributed in the hope that it will be useful,
  14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 # GNU General Public License for more details (read LICENSE.txt).
  17 #
  18 # You should have received a copy of the GNU General Public License
  19 # along with this program; if not, write to the Free Software
  20 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  21 #
  22 # $Id: DBConnection.py,v 1.20 2005/03/01 16:09:57 hmichelon Exp $
  23 #
  24 import string
  25 import sys
  26 #from mx import DateTime
  27 from pyPgSQL import libpq
  28 from pyPgSQL import PgSQL
  29
  30 class ConnectionParameter:
  31     def __init__(self, name="", user="", password="", db="", local=False, host="", port="5432"):
  32         self.name = name
  33
  34         self.user = user
  35         self.password = password
  36         self.db = db
  37
  38         self.local = local
  39
  40         self.host = host
  41         self.port = port
  42
  43     def get_dsn(self):
  44         dsn = ""
  45         if (self.host is not None):
  46             dsn = self.host
  47
  48         dsn = dsn + ":"
  49
  50         if (self.port is not None):
  51             dsn = dsn + str(self.port)
  52
  53         dsn = dsn + ":"
  54
  55         if (self.db is not None):
  56             dsn = dsn + self.db
  57
  58         dsn = dsn + ":"
  59
  60         if (self.user is not None):
  61             dsn = dsn + self.user
  62
  63         dsn = dsn + ":"
  64         if (self.password is not None):
  65             dsn = dsn + self.password
  66
  67         return dsn
  68     def dump(self):
  69         print "NAME=%s : user=%s, password=%s, db=%s, local=%s, host=%s, port=%s"%(self.name, self.user, self.password, self.db, self.local, self.host, self.port)
  70
  71
  72 DatabaseError = libpq.DatabaseError
  73
  74 class DBConnection:
  75   """Database connection/deconnection and query execution"""
  76
  77   def __init__(self):
  78     self.db = None
  79
  80   def connect(self, connectionParameter):
  81     """Try to connect to a database"""
  82     self.connectionParameter = connectionParameter
  83     #self.db = MyPgSQL.connect(dsn) #delete see svn history for MyPgSQL.py. i dunno why this was necessary
  84     self.db = PgSQL.connect(connectionParameter.get_dsn())
  85     self.db.autocommit = 1
  86     return self.db
  87
  88
  89   def pgversion(self):
  90     if (self.is_connected()):
  91       v = string.split(str(self.db.version), ',')
  92       return v.pop(0)
  93     return ''
  94
  95
  96   def query(self, sql):
  97     """Execute a query and return the corresponding DB-API cursor."""
  98     if not self.is_connected() : return None
  99     cursor = self.db.cursor()
 100     try:
 101       cursor.execute("SET CLIENT_ENCODING TO 'UTF-8'")
 102       cursor.execute(sql)
 103     except libpq.OperationalError, msg:
 104       cursor.close()
 105       return { 'error' : str(msg), 'notices' : self.db.notices }
 106     return { 'cursor' : cursor, 'notices' : self.db.notices }
 107
 108
 109   def commit(self):
 110     if not self.is_connected() : return
 111     self.db.commit()
 112
 113
 114   def is_connected(self):
 115     return (self.db != None)
 116
 117
 118   def disconnect(self):
 119     if not self.is_connected() : return
 120     self.db.close()
 121     self.db = None