Text 7742, 71 rader
Skriven 2005-10-19 00:08:12 av Randall Parker (1:379/45)
   Kommentar till text 7734 av Paul Ranson (1:379/45)
Ärende: Re: GPL and linking and MySQL ADO.NET driver
====================================================
From: Randall Parker <obfuscate_techieSPAMpundit_now@STOPfutureSPAMpundit_with_
bold_stuff.comNOW>

Paul,

I'm amazed at just how much ADO.Net seems a step backward from an object
oriented
standpoint.

In Java with JDBC one had to instantiate just a single class somewhere that was
for a
specific driver. With ADO.Net one has to instantiate a number of different
driver-specific classes for a driver.  I'm still learning this but with MySQL
as an
example I know 3 you can to refer to so far:

         MySql.Data.MySqlClient.MySqlConnection dbConn;
         MySql.Data.MySqlClient.MySqlCommand dbCmd;
         MySql.Data.MySqlClient.MySqlDataAdapter dbAdapter;

          dbConn = new MySqlConnection(MyConnString);
          dbConn.Open();
          dbCmd = new MySql.Data.MySqlClient.MySqlCommand();
          dbAdapter = new MySql.Data.MySqlClient.MySqlDataAdapter();

Now, for some of them you can assign the instantiations to what are basically
base
interface types. But when you instantiate them you have to refer to their
names.

It would make a lot more sense if off the connection object you could get a
command
object and an adapter object (and some others). Then you wouldn't need to refer
to
the other driver-specific class names once you'd instantiated the connection
object.

I said on an MS forum that this seemed dumb and one of the MVPs said he didn't
see a
way around the way it works.

However, with Java you can load the class name at start-up and do reflection or
something else to instantiate a class name. Perhaps with C# and ADO.Net you
might be
able to load the class name as a string and somehow instantiate it and use
interface
types to declare variables? Not sure.


Paul Ranson wrote:
> That seems somewhat retarded. What's the point of abstraction if you have to
> know what you're going to be using at that level?
>
> Does the MySQL code not implement an OleDB provider? I'd have expected to
> just be able to name the data source but it's not my field.
>
> Paul
>
> "Randall Parker"
> <obfuscate_techieSPAMpundit_now@STOPfutureSPAMpundit_with_bold_stuff.comNOW>
> wrote in message news:435525bb$1@w3.nls.net...
>
>>Paul,
>>
>>You actually have to refer to the MySQL driver by name in your source
>>code. In C#:
>>
>>using MySql.Data.MySqlClient;

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