To connect to External database below is the sample code:

public static void renameCustAccountsinRetailDB(CustAccount _oldName = "",

                                                CustAccount _newName = "" )

{

    #OCCRetryCount

    LoginProperty                 loginProperty;

    OdbcConnection                odbcConnection;

    Statement                     statement;

    ResultSet                     resultSet;

    str                           sql;

    SqlStatementExecutePermission perm;

    Map           mapRetailTables  =  new Map(Types::String,Types::String);

    MapEnumerator enumerator;

    mapRetailTables.insert('POSTRANSACTION','CUSTACCOUNT');

    mapRetailTables.insert('RETAILPUBRETAILCHANNELTABLE','DEFAULTCUSTACCOUNT');

    mapRetailTables.insert('RETAILCOUPONISSUERTABLE','CUSTACCOUNT');

    mapRetailTables.insert('RETAILCHANNELTABLE','DEFAULTCUSTACCOUNT');

    mapRetailTables.insert('RETAILPUBRETAILSTORETABLE','USEDEFAULTCUSTACCOUNT');

    mapRetailTables.insert('RETAILTRANSACTIONLOYALTYREWARDPOINTTRANS','CUSTACCOUNT');

    mapRetailTables.insert('RETAILTRANSACTIONTABLE','CUSTACCOUNT');

    mapRetailTables.insert('RETAILSTORETABLE','USEDEFAULTCUSTACCOUNT');

    mapRetailTables.insert('RETAILTRANSACTIONSALESTRANS','CUSTACCOUNT');

    mapRetailTables.insert('RETAILCUSTAFFILIATION','CUSTACCOUNTNUM');

    //ODBC Conection

    //Set information on the ODBC

    loginProperty = new LoginProperty();

    loginProperty.setDSN("RetailDSN");

    loginProperty.setDatabase("SICCSTOREDB2");

    try

    {

        //Create connection to external DB

        odbcConnection = new OdbcConnection(loginProperty);

        if (odbcConnection)

        {

            while (enumerator.moveNext())

            {

                sql = "update "+ enumerator.currentKey() +" set "+ enumerator.currentValue()+" ="+ _newName+" where "+enumerator.currentValue()+" ="+ _oldName;

                //assert permission for sql string

                perm = new SqlStatementExecutePermission(sql);

                perm.assert();

                //Prepare statement

                statement = odbcConnection.createStatement();

                resultSet = statement.executeQuery(sql);

            }

            resultSet.close();

            statement.close();

        }

        else

        {

            error("Failed to log on to the database");

        }

    }

    catch

    {

        throw error(" Please try again");

    }

}