Error: "The underlying provider failed on Open" in Entity Framework application

My name is Archana CM from Microsoft SQL Developer Support team, we support many data access technologies including Entity Framework, SSIS. I had chance to work with developer who was having issues in his Entity Framework, one of the issue was while adding data to .mdf file which was on file system. In today’s blog…

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SQLExceptions while trying to perform add , delete or update operation using the DataGridView control

You may see some SQLExceptions while trying to perform add , delete or update operation using the DataGridView control in .net framework. This post will speak about Adding and Deleting rows to the relation tables using windows application using DataGridView control in .net Framework 4.0 using Visual Studio 2010. I have created 2 tables called…

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Things to keep in mind regarding Registry while migrating a 32 bit application from Vista x64 to Windows 7 x64

If you are migrating a 32 bit application from Vista x64  to Windows 7 x64 and your application relies on some information in registry. There are few things you should consider as following. In Windows 7, registry is virtualized. As a result, wow64 applications don’t have to explicitly provide registry path with Wow6432Node node. For…

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Why is my ConnectionString incorrect..?

Folks, I wanted to post this experience as I struggled for a couple of days trying to figure out what’s wrong in my connection string when I handled a migration scenario from Windows 2000 to Windows 2008. I had a bunch of VBScripts doing database update jobs running successfully over years on the Windows 2000/XP…

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Enterprise Library 4.1 DAB leaking oracle connections that participate in DTC transactions

We had a case recently where connection pooling was not happening properly when using Enterprise Library 4.1 Data Access Block with Oracle provider (ODP.Net). It was working properly from EL 3.1. Network trace and ODP.Net Connection Pooling trace revealed that a new physical connection was getting created for every open connection call even though previous…

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Connection leak , its symptoms and troubleshooting

  To know about connection leak you first need to have a basic idea of connection pooling. If you are not sure about connection pooling please visit the following link –: http://msdn.microsoft.com/en-us/library/ms810829.aspx http://msdn.microsoft.com/en-us/library/8xx3tyca(vs.71).aspx http://support.microsoft.com/default.aspx?scid=kb;%5BLN%5D;191572 Connection leak basically happens when we open a connection to the database from our application and forget to close it, or…

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How to convert an IEnumerable to a DataTable in the same way as we use ToList or ToArray

LINQ provides us some extension methods to convert an IEnumerable to a collection e.g. ToList(), ToArray() etc. But what if you want to convert the enumerable to a DataTable. There is no built in extension method for that currently.                   var v = (from x in collection Select x).ToDataTable();   But if required we…

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How to find out the data-reader referencing an ADO.NET connection object to fix the error: "There is already an open DataReader associated with this Command which must be closed first"

Sometimes while executing a DB command in ADO.NET we come across below error. There is already an open DataReader associated with this Command which must be closed first   Or   ERROR [HY000] [Microsoft][SQL Native Client]Connection is busy with results for another command   This error is generated when we try to execute some query…

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