[Tutor] module with static global

[János Juhász]

Dear Guys!

I am using a class for connecting to an sql database via odbc.
It is like this:

import dbi, odbc

class scalaDB:
      def __init__(self):
            self.cn =
odbc.odbc('DSN=scalaDB;UID=query;PWD=query;DATABASE=scalaDB')

      def closeDB(self):
            self.cn.close()

      def Execute(self, sql):
            cr = self.cn.cursor()
            cr.execute(sql)
            cr.close()

      def Query(self, sql):
            try:
                  cr = self.cn.cursor()
                  cr.execute(sql)
                  self.colnames = [field_prop[0] for field_prop in
cr.description]
                  self.result = cr.fetchall()
                  self.rownum = len(self.result)
                  return self.result
            except:
                  self.colnames = [None]
                  self.result = [[None]]
                  self.rownum = 0
                  return [[None]]

      def QueryValue(self, sql):
            try:
                  cr = self.cn.cursor()
                  cr.execute(sql)
                  self.colnames = [field_prop[0] for field_prop in
cr.description]
                  self.result = cr.fetchall()
                  self.rownum = len(self.result)
                  return self.result[0][0]
            except:
                  self.colnames = [None]
                  self.result = None
                  self.rownum = 0
                  return None

I also have some other classes represented in this database as records. As
the records are in the database, they has to have a scalaDB instance for
running any sql statement on it. Currently I send a scalaDB instance to
every record-based class in the __init__(): proc.

class Component:
      def __init__(self, scalaDB, StockCode, Qty=1, Parent=None):
            self.scalaDB = scalaDB
            self.StockCode = StockCode
            self.Parent = Parent
            self.Qty = Qty                                        ## Qty in
the BOM
            self.Components = self.GetComponents()

      def GetParent(self):
            return self.Parent

      def __getattr__(self, name):
            if 'SC' in name:k
                  value = self.scalaDB.QueryValue("select %s from SC010100
where SC01001 = '%s'" % (name, self.StockCode) )
                  return value



How have I modify this to use my scalaDB class in this way:

>>>import scalaDB
>>>xy  = scalaDB.Query(sql)



Best regards,
Janos Juhasz