Unable to update the EntitySet ‘Table’ because it has a DefiningQuery and no element exists in the element to support the current operation

Entity Framework tried to add a record to a table which had Clustered Index but it didn't have Primary Key.

Simple solution was adding the Primary Key.

the reason is treating the table as View, then the EDMX file keep the table as a view in StorageModel\EntitySet\DefiningQuery element. When there is a DefiningQuery the Entity becomes readonly unless you add modification functions, the other solution can be adding modification functions like Stored Procedures for Inserting, Updating, and Deleting.

Unable to update the EntitySet ‘Table’ because it has a DefiningQuery and no element exists in the element to support the current operation

{System.Data.EntityException: The underlying provider failed on Open.

Entity Framework 5.0 with DbContext in the code tried to have access data as data Access layer code of a WCF service, the following error happened:

{System.Data.EntityException: The underlying provider failed on Open. ---> System.Data.SqlClient.SqlException: Connection Timeout Expired. The time out period elapsed during the post-login phase. The connection could have timed out while waiting for server to complete the login process and respond; Or it could have timed out while attempting to create multiple active connections. The duration spent while attempting to connect to this server was - [Pre-Login] initialization=50; handshake=1215; [Login] initialization=0; authentication=14; [Post-Login] complete=13022; ---> System.ComponentModel.Win32Exception: The wait operation timed out

It didn't have Transaction around the code, if I had a TransactionScope around the code then it treat connections as multiple ones using a distributed transaction which force open/close connections with each call. But without the transaction I needed to add opening connection code.

using (MyEntities ctx = new MyEntities()) { #region Added to work when Transaction is not around ctx.Database.Connection.Open(); #endregion courseList = ctx.MyMethod(MyParam).ToList(); }

{System.Data.EntityException: The underlying provider failed on Open.

DbEntityValidationException - Entity framework validation error handling

A sample code to catch part of an error handling when dealing with Entity Framework.

try { ... } catch (DbEntityValidationException dbEx) { #region LINQ query to get EF DB entity validation errors /* var errMsgs = dbEx.EntityValidationErrors .SelectMany(x => x.ValidationErrors) .Select(x => x.ErrorMessage).ToArray(); var exceptionFullErrMsg = string.Concat( dbEx.Message, " Validation errors (DbEntityValidationException): " + UtilityHelper.ErrMsgBuilder(errMsgs)); log.Error(exceptionFullErrMsg); */ #endregion #region Loop to find Entity Framework DB entity validation errors foreach (var validationErrors in dbEx.EntityValidationErrors) foreach (var validationError in validationErrors.ValidationErrors) log.Error(UtilityHelper.ErrMsgBuilder(new string[] { "DbEntityValidationException" , validationError.ErrorMessage } )); #endregion } catch (Exception ex) { #region Exception logging log.Error(UtilityHelper.ErrMsgBuilder( new string[] { ex.GetType().Name } ), ex); #endregion } finally { ... } ... #region Utility Helper class public class UtilityHelper { public static string ErrMsgBuilder(String[] msgArray) { StringBuilder sbErr = new StringBuilder(); foreach (string msg in msgArray) sbErr.AppendLine(msg); return sbErr.ToString(); } } #endregion

DbEntityValidationException - Entity framework validation error handling

Unable to update the EntitySet 'EntityName' because it has a DefiningQuery and no element exists in the element to support the current operation.

Tied to debug my unit [TestMethod] in a unit test project through Test Explorer in Visual Studio 2012, then it tried to save the entity changes in database through a DbContext and it throw the folowing error message: 'Unable to update the EntitySet 'EntityName' because it has a DefiningQuery and no element exists in the element to support the current operation.'

In my case the problem was incorrect Entity Key setting on my entity in EF Model plus forgetting to set primary key in DB table. After setting primary key for the table which entity pointing too, I needed to update the model and open the EF model and manualy set Entity Key for primary key related member in the entity and clearing Entity Key setting for unnecessary entity members. Then rebuild, it worked. The reason was EF created a compound key made of all non nullable entity members which I had to reset them all.

It was my case but there are other possibilities for this error which already discussed if you search on Internet (Google or bing it)

Unable to update the EntitySet 'EntityName' because it has a DefiningQuery and no element exists in the element to support the current operation.