Re: Some new (or old ?) information


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Thread: Re: Some new (or old ?) information

  1. #1
    Dennes Torres Guest

    Re: Some new (or old ?) information


    Hi!

    I found this text at the address http://msdn.microsoft.com/library/de...doplusnet.asp:

    "Server Cursors

    "As I described earlier, ADO's recordset was really a conflation of
    three different APIs - the interface for a forward-only stream of data,
    the API for a client-side cache (the OLE DB cursor engine), and an abstraction
    for exposing updateable, scrollable cursors. The first two map to the ADO+
    DataReader and DataSet classes, respectively. So what happened to server
    cursors? ADO+ currently does not have intrinsic support for a general-purpose
    server cursor object. The key reason for this is that for this kind of functionality,
    data sources tend to differ in their implementation enough that exposing
    a single abstraction that hides the details from the user becomes difficult.

    "Since most applications require only the first two abstractions anyway,
    ADO+ relies on ADO for server cursor support, at least for the current beta
    of Visual Studio .NET. ADO is readily accessible from the .NET Framework
    through the COM Interop services of the CLR. The TLBIMP program, shipped
    with the SDK, can be used to import a COM type library and emit metadata
    that can be consumed by the CLR. Therefore, for developers who really want
    ADO semantics, or ones who rely heavily on positioned updates and connected
    scrollable cursors, using ADO through the Interop layer is the right solution."

    This mean that client/server programmers will need to forget RAD an things
    like Data Environment to learn a new language in wich they need to do all
    the data manipulation in code, because the visual components don't support
    server-side cursors that the client/server environment need? I really don't
    think this will work.

    I tried to use VB6 components in VB.NET: I used the ADODC and DataGrid
    in VB.NET. After configured ADODC properties, I couldn't bind the DataGrid
    to the ADODC control, ADODC wasn't listed in datasource property. I tried
    by code but it doesn't work. I think I made something wrong, but it isn't
    a trivial task. So the question is:

    Why should I use VB.NET if:

    A) My systems work well with the language that I already know, VB 6.0
    B) I can't user VB.NET power, because it wasn't made for client/server
    C) I can't even user VB 6.0 components with VB.NET, it's too difficult (more
    difficult than VB 6.0 and with nothing better, I mean)

    Am I forgetting something? I'm surprised that nobody has notice this before!
    What am I forgetting?

    []'s

    Dennes Torres


  2. #2
    Patrick Troughton Guest

    Re: Some new (or old ?) information


    >This mean that client/server programmers will need to forget RAD an things
    >like Data Environment to learn a new language in wich they need to do all
    >the data manipulation in code, because the visual components don't support
    >server-side cursors that the client/server environment need? I really don't
    >think this will work.


    There are a lot of drag and drop RAD tools in .NET that let you do lots of
    data work without writing code. Honestly, I'm not a big fan of data binding
    and prefer to write my own code so I haven't really tried them, but they
    are there. Have you had a look at Database Programming with Visual Basic.NET
    by Apress? I'm sure it covers the new RAD tools in more detail than I can
    provide....

    http://www.apress.com/catalog/book/1893115291/

    /Pat

  3. #3
    Dennes Torres Guest

    Re: Some new (or old ?) information



    Hi !

    I know that. What I'm saying is that if I want to use server-side cursors
    I couldn't user RAD, because I will need to use ADO by code. All the RAD
    in .NET use client-side cursors.

    I think this will be a big problem in migration process, specially in migration
    process made by unprepared people.

    []'s

    Dennes Torres

    "Patrick Troughton" <Patrick@Troughton.com> wrote:
    >
    >>This mean that client/server programmers will need to forget RAD an things
    >>like Data Environment to learn a new language in wich they need to do all
    >>the data manipulation in code, because the visual components don't support
    >>server-side cursors that the client/server environment need? I really don't
    >>think this will work.

    >
    >There are a lot of drag and drop RAD tools in .NET that let you do lots

    of
    >data work without writing code. Honestly, I'm not a big fan of data binding
    >and prefer to write my own code so I haven't really tried them, but they
    >are there. Have you had a look at Database Programming with Visual Basic.NET
    >by Apress? I'm sure it covers the new RAD tools in more detail than I can
    >provide....
    >
    >http://www.apress.com/catalog/book/1893115291/
    >
    >/Pat



  4. #4
    Rob Teixeira Guest

    Re: Some new (or old ?) information



    Hello Dennes,
    Nice to see another name from Brazil!

    I think anyone involved with migration will tell you that it is an exercise
    that's going to require some thought and planning. In some cases, it will
    be much easier than others. Middle-tier business logic components will be
    extremely simple, for example. UI code will be a more involved process.
    People like Dan Appleman have given this aspect of development a lot of thought
    (he has a great book about migration!), but even he refuses to say that it
    is a painless process for all cases.

    In this respect though, server-side cursors present such a scalability problem
    (and that's been known for decades), that I have to wonder how many people
    really use it (within a VB context)?
    That's a real question by the way
    Feel free to post your thoughts. I'm curious now.

    -Rob


    "Dennes Torres" <dennes@bufaloinfo.com.br> wrote:
    >
    >
    >Hi !
    >
    >I know that. What I'm saying is that if I want to use server-side cursors
    >I couldn't user RAD, because I will need to use ADO by code. All the RAD
    >in .NET use client-side cursors.
    >
    >I think this will be a big problem in migration process, specially in migration
    >process made by unprepared people.
    >
    >[]'s
    >
    >Dennes Torres
    >



  5. #5
    Dennes Torres Guest

    Re: Some new (or old ?) information



    Hi, Rob !

    A lot, very lot, people use server-side cursors. Think in data grid, for
    example. I don't want to transfer all the records just for the user look
    to the grid and close the window. So I can transfer just a few records and
    get the rest just if needed, if the user press "page down", for example.

    Some people can say that a good interface can avoid data grids, for example.
    I agree that a lot of client/server interfaces can avoid it, but do you think
    every interface can ? I don't think so.

    So, the problem is not the migration, but even the creation of new application.
    Is possible to design every (EVERY!) user interface avoiding the use of data
    grid and navigation screens and using client side cursors ? I don't think
    so.

    The second problem is the knowledge of the people. In Brazil we have a lot
    (a lot !) of people that even know client/server well. The server-side cursor
    is a bless (is it correct ?) for bad user interfaces. So, when all this people
    begin to use VB.NET we will see lots and lots of problems in TI area.

    []'s

    Dennes Torres



    "Rob Teixeira" <RobTeixeira@@msn.com> wrote:
    >
    >
    >Hello Dennes,
    >Nice to see another name from Brazil!
    >
    >I think anyone involved with migration will tell you that it is an exercise
    >that's going to require some thought and planning. In some cases, it will
    >be much easier than others. Middle-tier business logic components will be
    >extremely simple, for example. UI code will be a more involved process.
    >People like Dan Appleman have given this aspect of development a lot of

    thought
    >(he has a great book about migration!), but even he refuses to say that

    it
    >is a painless process for all cases.
    >
    >In this respect though, server-side cursors present such a scalability problem
    >(and that's been known for decades), that I have to wonder how many people
    >really use it (within a VB context)?
    >That's a real question by the way
    >Feel free to post your thoughts. I'm curious now.
    >
    >-Rob
    >
    >
    >"Dennes Torres" <dennes@bufaloinfo.com.br> wrote:
    >>
    >>
    >>Hi !
    >>
    >>I know that. What I'm saying is that if I want to use server-side cursors
    >>I couldn't user RAD, because I will need to use ADO by code. All the RAD
    >>in .NET use client-side cursors.
    >>
    >>I think this will be a big problem in migration process, specially in migration
    >>process made by unprepared people.
    >>
    >>[]'s
    >>
    >>Dennes Torres
    >>

    >



  6. #6
    Mike Mitchell Guest

    Re: Some new (or old ?) information

    On 15 Dec 2001 00:25:39 GMT, "Dennes Torres"
    <dennes@bufaloinfo.com.br> wrote:

    >Some people can say that a good interface can avoid data grids, for example.


    Why avoid data grids? They are the best all-round presentational tool
    for displaying and manipulating data since the spreadsheet was
    invented. Tree views have their place, but a grid, especially a highly
    configurable one like VsFlexGrid Pro, allows users to do anything they
    need -- and stuff they don't.

    Ask yourself, why are there so many grids on the market? It's what
    people -- developers and clients -- want.

    MM

  7. #7
    Dennes Torres Guest

    Re: Some new (or old ?) information



    Hi, Mike !

    That's what I'm saying and trying to discover to/from everyone !

    The fact is : Without server side cursors, whe can't use datagrids in winforms/vb.net
    any more, because the network traffic will be too big !

    A lot of people are saying that an interface with a grid is a bad interface.
    I agree in part. Some interfaces use more grids than necessary and could
    avoid it, but a lot of interfaces can't and, without server-side cursors,
    this interfaces can't be made in winforms !

    []'s

    Dennes Torres


    kylix_is@yahoo.co.uk (Mike Mitchell) wrote:
    >On 15 Dec 2001 00:25:39 GMT, "Dennes Torres"
    ><dennes@bufaloinfo.com.br> wrote:
    >
    >>Some people can say that a good interface can avoid data grids, for example.

    >
    >Why avoid data grids? They are the best all-round presentational tool
    >for displaying and manipulating data since the spreadsheet was
    >invented. Tree views have their place, but a grid, especially a highly
    >configurable one like VsFlexGrid Pro, allows users to do anything they
    >need -- and stuff they don't.
    >
    >Ask yourself, why are there so many grids on the market? It's what
    >people -- developers and clients -- want.
    >
    >MM



  8. #8
    Markn Guest

    Re: Some new (or old ?) information


    You can still use datagrids. You may not be able to use databound datagrids.
    Not being able to do this may slow down development but is better in the
    long run. Suppling data to the grid through an interface (as Patrick suggested)
    is the way to go. I do this in another language with grids and it works
    well.

    Mark

    "Dennes Torres" <dennes@bufaloinfo.com.br> wrote:
    >
    >
    >Hi, Mike !
    >
    >That's what I'm saying and trying to discover to/from everyone !
    >
    >The fact is : Without server side cursors, whe can't use datagrids in winforms/vb.net
    >any more, because the network traffic will be too big !
    >
    >A lot of people are saying that an interface with a grid is a bad interface.
    >I agree in part. Some interfaces use more grids than necessary and could
    >avoid it, but a lot of interfaces can't and, without server-side cursors,
    >this interfaces can't be made in winforms !
    >
    >[]'s
    >
    >Dennes Torres
    >
    >
    >kylix_is@yahoo.co.uk (Mike Mitchell) wrote:
    >>On 15 Dec 2001 00:25:39 GMT, "Dennes Torres"
    >><dennes@bufaloinfo.com.br> wrote:
    >>
    >>>Some people can say that a good interface can avoid data grids, for example.

    >>
    >>Why avoid data grids? They are the best all-round presentational tool
    >>for displaying and manipulating data since the spreadsheet was
    >>invented. Tree views have their place, but a grid, especially a highly
    >>configurable one like VsFlexGrid Pro, allows users to do anything they
    >>need -- and stuff they don't.
    >>
    >>Ask yourself, why are there so many grids on the market? It's what
    >>people -- developers and clients -- want.
    >>
    >>MM

    >



  9. #9
    Dennes Torres Guest

    Re: Some new (or old ?) information


    "Markn" <mnuttall@nospam.com> wrote:
    >
    >You can still use datagrids. You may not be able to use databound datagrids.
    > Not being able to do this may slow down development but is better in the


    Hi!

    If I can't use Data bound, why it's still there ? There is something wrong
    !

    []'s

    Dennes Torres


    >long run. Suppling data to the grid through an interface (as Patrick suggested)
    >is the way to go. I do this in another language with grids and it works
    >well.
    >
    >Mark
    >
    >"Dennes Torres" <dennes@bufaloinfo.com.br> wrote:
    >>
    >>
    >>Hi, Mike !
    >>
    >>That's what I'm saying and trying to discover to/from everyone !
    >>
    >>The fact is : Without server side cursors, whe can't use datagrids in winforms/vb.net
    >>any more, because the network traffic will be too big !
    >>
    >>A lot of people are saying that an interface with a grid is a bad interface.
    >>I agree in part. Some interfaces use more grids than necessary and could
    >>avoid it, but a lot of interfaces can't and, without server-side cursors,
    >>this interfaces can't be made in winforms !
    >>
    >>[]'s
    >>
    >>Dennes Torres
    >>
    >>
    >>kylix_is@yahoo.co.uk (Mike Mitchell) wrote:
    >>>On 15 Dec 2001 00:25:39 GMT, "Dennes Torres"
    >>><dennes@bufaloinfo.com.br> wrote:
    >>>
    >>>>Some people can say that a good interface can avoid data grids, for example.
    >>>
    >>>Why avoid data grids? They are the best all-round presentational tool
    >>>for displaying and manipulating data since the spreadsheet was
    >>>invented. Tree views have their place, but a grid, especially a highly
    >>>configurable one like VsFlexGrid Pro, allows users to do anything they
    >>>need -- and stuff they don't.
    >>>
    >>>Ask yourself, why are there so many grids on the market? It's what
    >>>people -- developers and clients -- want.
    >>>
    >>>MM

    >>

    >



  10. #10
    Patrick Troughton Guest

    Re: Some new (or old ?) information


    "Dennes Torres" <dennes@bufaloinfo.com.br> wrote:
    >Hi!
    >
    >If I can't use Data bound, why it's still there ? There is something wrong
    >!


    I think you might have lost me. You *can* use databinding in .NET. We discussed
    this a few times already...

    /Pat

  11. #11
    Dennes Torres Guest

    Re: Some new (or old ?) information



    Hi!

    No, you lost me.

    I can't use databind with server-side cursors.

    I can't use databind use client-side cursors because I will create lots of
    network traffic.

    For everything else I will need to make lots of code.

    So, I can't use databinding.

    []'s

    Dennes Torres


    "Patrick Troughton" <Patrick@Troughton.com> wrote:
    >
    >"Dennes Torres" <dennes@bufaloinfo.com.br> wrote:
    >>Hi!
    >>
    >>If I can't use Data bound, why it's still there ? There is something wrong
    >>!

    >
    >I think you might have lost me. You *can* use databinding in .NET. We discussed
    >this a few times already...
    >
    >/Pat



  12. #12
    Patrick Troughton Guest

    Re: Some new (or old ?) information


    "Dennes Torres" <dennes@bufaloinfo.com.br> wrote:
    >
    >I can't use databind with server-side cursors.


    Not accurate - you can with DataReaders. We went over this before.

    >I can't use databind use client-side cursors because I will create lots

    of
    >network traffic.


    You'll still get network traffic with server side cursors because the data
    still has to be moved across. If you're so concerned about network traffic,
    have you thought about putting your database objects on the database itself?
    This would minimize network traffic while allowing you to do databinding.
    That's what you want, right?

    >For everything else I will need to make lots of code.


    That's your choice.

    >So, I can't use databinding.


    Yes, you can. You're just choosing not to.

    Can I have a little clarification? Are you asking for advice or do you just
    want to complain? If the latter, there's no point in us trying to help you
    because no matter what we suggest, you're not going to be happy.

    /Pat

  13. #13
    Patrick Troughton Guest

    Re: Some new (or old ?) information


    "Patrick Troughton" <Patrick@Troughton.com> wrote:
    >
    >have you thought about putting your database objects on the database
    >itself?


    To be clear, I meant to say .... "on the database SERVER itself".

    /Pat



  14. #14
    MarkN Guest

    Re: Some new (or old ?) information


    Didn't mean impossible. My theory why these tools exist: For people who can't
    live without them and backwards compatiblity. They are not a good way to
    do enterprise development. What Patrick is saying is right and is the reason
    I gave up on them years ago. They are bad for so many reasons )(Network
    traffic/tie UI to database/Wierd errors). Bite the bullet(unless one lives
    where MM does and aren't allowed to have any) and get rid of them when you
    move to .NET. ALOT (I would venture saying the majority) of apps here in
    the States will need to do the same thing so don't feel like you are alone.


    >
    >If I can't use Data bound, why it's still there ? There is something wrong
    >!
    >
    >[]'s
    >
    >Dennes Torres
    >
    >
    >>long run. Suppling data to the grid through an interface (as Patrick suggested)
    >>is the way to go. I do this in another language with grids and it works
    >>well.
    >>
    >>Mark
    >>
    >>"Dennes Torres" <dennes@bufaloinfo.com.br> wrote:
    >>>
    >>>
    >>>Hi, Mike !
    >>>
    >>>That's what I'm saying and trying to discover to/from everyone !
    >>>
    >>>The fact is : Without server side cursors, whe can't use datagrids in

    winforms/vb.net
    >>>any more, because the network traffic will be too big !
    >>>
    >>>A lot of people are saying that an interface with a grid is a bad interface.
    >>>I agree in part. Some interfaces use more grids than necessary and could
    >>>avoid it, but a lot of interfaces can't and, without server-side cursors,
    >>>this interfaces can't be made in winforms !
    >>>
    >>>[]'s
    >>>
    >>>Dennes Torres
    >>>
    >>>
    >>>kylix_is@yahoo.co.uk (Mike Mitchell) wrote:
    >>>>On 15 Dec 2001 00:25:39 GMT, "Dennes Torres"
    >>>><dennes@bufaloinfo.com.br> wrote:
    >>>>
    >>>>>Some people can say that a good interface can avoid data grids, for

    example.
    >>>>
    >>>>Why avoid data grids? They are the best all-round presentational tool
    >>>>for displaying and manipulating data since the spreadsheet was
    >>>>invented. Tree views have their place, but a grid, especially a highly
    >>>>configurable one like VsFlexGrid Pro, allows users to do anything they
    >>>>need -- and stuff they don't.
    >>>>
    >>>>Ask yourself, why are there so many grids on the market? It's what
    >>>>people -- developers and clients -- want.
    >>>>
    >>>>MM
    >>>

    >>

    >



  15. #15
    Vlad Ivanov Guest

    Re: Some new (or old ?) information


    >>>>The fact is : Without server side cursors, whe can't use datagrids in

    >winforms/vb.net
    >>>>any more, because the network traffic will be too big !


    This is a concensus of so called professional community???

    What is wrong with disconnected recordsets forwarded ByVal to client-side
    to display a grid? Don't even start with network traffic - you don't need
    to show all of the available records if you provide a decent interface to
    query the data beforhand.




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