#!/usr/bin/python """ Module Name: oracleBrowse Description: Plug in for PythonCard application dbBrowse to provide Oracle specific functionality Constant/configuration values are currently maintained in the source code. If we are to optimise this application they should be split into seperate configuration files (as per PythonCard/Webware style guidelines) The structure of this module should be replicated for different RDBMS so that they can be interchanged by dbBrowse - hopefully. The only manipulation to data is to format date values as DD-Mon-YYYY This module currently relies on cx_Oracle to access Oracle. It should be expanded to use other DB-API compatible access modules. Changes; 04-Apr-2002 Changed the format of columnDefs that is passed from the db handler modules back to dbBrowser in the getColumns method. This actually makes the code in this module simpler, which must be a good thing """ __version__='$Revision: 1.9 $'[11:-2] __date__='9th November 2001' __author__='Andy Todd <andy47@halfcooked.com>' try: import cx_Oracle oracle = cx_Oracle except ImportError: import DCOracle2 oracle = DCOracle2 class browse: # Connection should be a dictionary with at least three keys, 'username', # 'password', 'database' - may need to be normalised for other RDBMS def __init__(self, connection): "Setup the database connection" # self._system_tables=['columns_priv', 'db', 'host', 'tables_priv', 'user'] # Not providing some values is guaranteed to ruin our connection if ('username' not in connection) and ('password' not in connection): raise ValueError connectString = connection['username']+'/'+connection['password'] if 'database' in connection: if connection['database']: connectString += '@' + connection['database'] self._db = oracle.connect( connectString ) self._cursor=self._db.cursor() # This one is used in getRow self._tableName='' def getTables(self): "Return a list of all of the non-system tables in schema <username>" stmt = 'SELECT table_name FROM user_tables' self._cursor.execute(stmt) return [ tableName[0] for tableName in self._cursor.fetchall() ] def getColumns(self, tableName): "Get the definition of the columns in tableName" # Have to make the data types lower case to keep in line with MySQL # format of dbBrowser column definitions is # column name, data type, length (for display), nullable, key, default stmt = """SELECT column_name, lower(data_type) data_type, decode(data_type, 'DATE', 11, 'NUMBER', nvl(data_precision, 38), data_length) precision, decode(nullable, 'Y', 'YES') nullable, ' ' key, ' ' default_value, ' ' extra FROM user_tab_columns WHERE table_name = '%s'""" % tableName self._cursor.execute(stmt) return self._cursor.fetchall() def getQueryString(self, tableName): "Return a SQL statement which queries all of the columns in tableName" tableStructure=self.getColumns(tableName) # Construct and return the string stmt='SELECT ' for columnList in tableStructure: # if columnList[1]=='DATE': # stmt+='date_format('+columnList[0]+", '%d-%b-%Y'), " # else: stmt+=columnList[0]+', ' stmt=stmt[:-2]+' FROM '+tableName return stmt def getRow(self, tableName): "Get a row from tableName" # When we upgrade to 2.2 this will be a great candidate for a # generator/iterator. In the meantime we use self._tableName to keep # track of what we are doing if tableName!=self._tableName: self._tableName=tableName self._cursor.execute(self.getQueryString(tableName)) return self._cursor.fetchone() def getRows(self, tableName): "Get all of the rows from tableName" if tableName!=self._tableName: self._tableName=tableName self._cursor.execute(self.getQueryString(tableName)) return self._cursor.fetchall() if __name__ == '__main__': # We are in an interactive session so run our test routines # Connect to the database connection={ 'username':'andy' ,'password':'andy' ,'database':'' } dbHolder = browse(connection) # Return all of our table names into user_tables user_tables = dbHolder.getTables() # Print out the structure of each table and its first row print "--------------------------------------------------" for table in user_tables: print dbHolder.getQueryString(table) # print dbHolder.getRow(table) print "--------------------------------------------------"