Many thanks for the clarification, gentelmen. On 10/17/07, Richard Blewett <[EMAIL PROTECTED]> wrote: > Dispose also returns the connection to the connection pool > > Regards > > Richard Blewett - DevelopMentor > > > -----Original Message----- > > From: Discussion of advanced .NET topics. [mailto:ADVANCED- > > [EMAIL PROTECTED] On Behalf Of Smotritsky, Alex > > Sent: 16 October 2007 22:01 > > To: [email protected] > > Subject: Re: [ADVANCED-DOTNET] Singleton and Database Connection > > challange > > > > The open and close methods of the connection object in ado.net usually > > take the connection from the connection pool on open and return it on > > close so you get connection pooling for free. > > > > -----Original Message----- > > From: Discussion of advanced .NET topics. > > [mailto:[EMAIL PROTECTED] On Behalf Of Mike Andrews > > Sent: Tuesday, October 16, 2007 2:34 PM > > To: [email protected] > > Subject: Re: [ADVANCED-DOTNET] Singleton and Database Connection > > challange > > > > This is not the place for a singleton and the singleton is not > > implemented > > correctly since it doesn't take into account any race conditions that > > might > > occur with a multi-threaded app such as asp.net. Also you would not > > want to > > dispose of the connection in the singleton since that defeats the > > purpose of > > the singleton. > > The connection should be created and destroyed when needed and not kept > > live > > by using the singleton. > > > > > > On 10/16/07, Abhijit Gadkari <[EMAIL PROTECTED]> wrote: > > > > > > We are writing an ASP.NET application. We have used singleton for > > > instantiating a database connection as explained in the following > > code > > > sample. > > > > > > > > > > > > Design thought was to use only one instance of MyDb across all the > > pages > > > in > > > this web application. Is this a correct singleton implementation for > > > Asp.NETweb application for managing database connection? In fact, > > this > > > code got C - > > > or D in our internal code review. Don't know why? Any idea on how to > > > improve > > > this code to A level. > > > > > > > > > > > > public sealed class AppDbProvider : IDisposable > > > > > > { > > > > > > public static readonly AppDbProvider instance = new > > > AppDbProvider(); > > > > > > > > > > > > private readonly MyDb _d = new MyDb(ConfigurationManager > > > .ConnectionStrings["my_connection"].ConnectionString, > > > > > > ConfigurationManager.ConnectionStrings[ > > > "my_connection"].ProviderName); > > > > > > > > > > > > public MyDb GetDbConnection() > > > > > > { > > > > > > if (_d != null) > > > > > > return _d; > > > > > > else > > > > > > throw new Exception("Problem with Database Connection > > in > > > AppDbProvider."); > > > > > > } > > > > > > > > > > > > #region IDisposable Members > > > > > > > > > > > > public void Dispose() > > > > > > { > > > > > > if (_d != null) > > > > > > _d.Dispose(); > > > > > > > > > > > > Dispose(); > > > > > > > > > > > > } > > > > > > > > > > > > #endregion > > > > > > } > > > > > > > > > > > > Now in code behind file, we have following code > > > > > > > > > > > > > > > > > > public partial class CreatePage > > > > > > { > > > > > > private AmgDb _d; > > > > > > > > > > > > try > > > > > > { > > > > > > _d = AppDbProvider.instance.GetDbConnection(); > > > > > > } > > > > > > Catch (Exception exce) > > > > > > { > > > > > > Response.write(exce.message); > > > > > > } > > > > > > > > > > > > } > > > > > > > > > > > > And in the end, in the page unload event we have following cleanup > > code > > > > > > > > > > > > protected void Page_Unload(object sender, EventArgs e) > > > > > > { > > > > > > if (_d != null) > > > > > > { > > > > > > _d = null; > > > > > > } > > > > > > } > > > > > > =================================== > > > This list is hosted by DevelopMentor(r) http://www.develop.com > > > > > > View archives and manage your subscription(s) at > > > http://discuss.develop.com > > > > > > > =================================== > > This list is hosted by DevelopMentor(r) http://www.develop.com > > > > View archives and manage your subscription(s) at > > http://discuss.develop.com > > > > =================================== > > This list is hosted by DevelopMentor. http://www.develop.com > > > > View archives and manage your subscription(s) at > > http://discuss.develop.com > > =================================== > This list is hosted by DevelopMentor(r) http://www.develop.com > > View archives and manage your subscription(s) at http://discuss.develop.com >
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