Entity Framework Migrations Error - Sequence contains no elements

sequence contains no matching element entity framework
system.invalidoperationexception sequence contains no elements
source sequence doesn t contain any elements

command: add-migration blahblah -verbose error: Sequence contains no elements

I did a few things before getting this error. I made a change to my code-first model but did not runadd-migration yet. Then I added an EDMX model to play around with an idea visually. I realized the EDMX model was messing with my code so I removed it. I tried to run add-migration and got "Sequence contains no elements". I upgraded to EF 5 and uninstalled the old Migrations package except for my configurations. Then I tried add-migration again and I am still getting "Sequence contains no elements". Below is the rest of the error.

System.InvalidOperationException: Sequence contains no elements
   at System.Linq.Enumerable.Single[TSource](IEnumerable`1 source)
   at System.Data.Entity.Migrations.Infrastructure.EdmModelDiffer.GetQualifiedTableName(XDocument model, String entitySetName)
   at System.Data.Entity.Migrations.Infrastructure.EdmModelDiffer.<FindRenamedIndependentAssociationColumns>b__ba(<>f__AnonymousType16`2 <>h__TransparentIdentifieraa)
   at System.Linq.Enumerable.<>c__DisplayClass12`3.<CombineSelectors>b__11(TSource x)
   at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
   at System.Linq.Enumerable.<ConcatIterator>d__71`1.MoveNext()
   at System.Linq.Enumerable.<ConcatIterator>d__71`1.MoveNext()
   at System.Linq.Enumerable.<DistinctIterator>d__81`1.MoveNext()
   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
   at System.Data.Entity.Migrations.Infrastructure.EdmModelDiffer.Diff(XDocument sourceModel, XDocument targetModel, String connectionString)
   at System.Data.Entity.Migrations.DbMigrator.Scaffold(String migrationName, String namespace, Boolean ignoreChanges)
   at System.Data.Entity.Migrations.Design.MigrationScaffolder.Scaffold(String migrationName, Boolean ignoreChanges)
   at System.Data.Entity.Migrations.Design.ToolingFacade.ScaffoldRunner.Scaffold(MigrationScaffolder scaffolder)
   at System.Data.Entity.Migrations.Design.ToolingFacade.ScaffoldRunner.RunCore()
   at System.Data.Entity.Migrations.Design.ToolingFacade.BaseRunner.Run()
Sequence contains no elements

Looks like a bug. Do you mind filing it at http://entityframework.codeplex.com/workitem/list/advanced with details allowing to reproduce the problem?

Entity Framework Migrations Error, Looks like a bug. Do you mind filing it at http://entityframework.codeplex.com/​workitem/list/advanced with details allowing to reproduce the  Below is the rest of the error. System.InvalidOperationException: Sequence contains no elements at System.Linq.Enumerable.Single [TSource] (IEnumerable`1 source) at System.Data.Entity.Migrations.Infrastructure.EdmModelDiffer.GetQualifiedTableName (XDocument model, String entitySetName) at System.Data.Entity.Migrations.Infrastructure.EdmModelDiffer.<FindRenamedIndependentAssociationColumns>b__ba (<>f__AnonymousType16`2 <>h__TransparentIdentifieraa) at System.Linq.Enumerable.

This problem occurs to me when a try to define type and size of a column with DataAnnotations.

BAD:

[Column(TypeName="VARCHAR(254)")]
public string ColumnName { get; set; }

OK:

[MaxLength(254)]
[Column(TypeName="VARCHAR")]
public string ColumnName { get; set; }

Entity Framework Migrations Error : Sequence contains no elements , I have been search "mysql ef6: timestamp" and using this code for the time being, i don't know this the best solution for my question, is there  I have been create a project in VS2015 with entity framework 6 - Code First with; EntityFramework [6.0.0.0] mysql.data.entity.EF6 [6.8.3.0] I am try Migrations . command: Add-Migration Initial error: Sequence contains no matching element. I've been trying a bunch of things, and get the cause of this [Timestamp] public byte[] RowVersion { get

Migrations :: "Sequence contains no matching element" thrown , InvalidOperationException: Sequence contains no matching element at System.​Linq. Entity.DbModelBuilder.Build(DbProviderManifest providerManifest, DbProviderInfo providerInfo) at WriteEdmx(DbContext context, XmlWriter writer​) at System. IsUnique();; add another migration and the error occur. >>I receive this message:"The sequence contains no elements match"when execute this code: Could you please point out which line exactly caused this error? Because with your provide code, I made a test, however, it works correctly:

I ran into the same problem, I found this issue: Migrations: "Sequence contains no elements" in model differ after renaming PK property when self-referencing relationship with no FK property (independent association) which is the situation that I'm stuck with. it's a bug but there's a workaround suggested by a user which I think is a good solution:

"My table was self referencing, dropping the foreign key column and then adding a migration fixed the issue and allowed a rename of the property

Steps to fix, if it helps:

  1. Remove (Comment) self referencing foreign keys and scaffold a migration, Update-Database
  2. Rename problem column, Scaffold another migration, Update-Database
  3. Uncomment self referencing foreign keys and scaffold a migration, Update-Database
  4. Remove the code (but leave the migration) generated by steps 1 and 3

Testing the fix:

  1. Update database, target before step #1 migration
  2. Update-Database to most recent migration and make sure it doesn't fail."

"Sequence contains no elements" Error on Compile., command: add-migration blahblah -verbose error: Sequence contains no elements I did a few things before getting this error. I made a change to my code-​first  When I run the following code in my Seed method, the Package manager Console keeps throwing a "Sequence contains no elements" error. context.Countries.AddOrUpdate(c

This has happened to me when I was doing it for a small web project.

The web's .csproj failed to load one time and visual studio decided to change the default project to a random one that did load.

Because the app.config in the new default project did not contain any connectionStrings... EF could not find anywhere to update.

Changing my default project back to my web project, by right clicking the project and selecting Set As Startup Project, solved this for me.

But I guess the issue here was that EF was looking for the first connection string in the default config, and the number of strings available was 0.

System.InvalidOperationException: Sequence contains no elements, "Sequence contains no elements" error during migration using TFS Integration Tools Mar 2012 release NET Entity Framework and LINQ to Entities. path('')  I had a bug where I got a System.InvalidOperationException with the message Sequence contains no matching element because I had an incorrect string value being passed to .HasColumnType() in my table configuration.

Install Error "Sequence contains no elements", NET Entity Framework and LINQ to Entities. a System. to Entities. I am getting sequence contains no element error when this statement is hit: CurrentContext. a) install Entity Developer Professional Trial for migrating (you can uninstall it after the migration is done, it is needed because it supports System.Data.SqlClient) b) run your code to create the database objects in SQL Server c) create the *.edml model (Devart Entity Model) and add all your tables from SQL Server in the model

ToListAsync() fails on ASP NET CORE but ToList() works, I tried to upgrade to the latest version of Remote Support, 5.5.5, and I got an error. "Sequence contains no elements" is basically LINQ's way of telling you that you're trying to reference an element from a list that doesn't have anything. So calls to things like .First() or .Single() can't find anything, hence the error.

MVC, Sequence contains no matching element, ToListAsync() fails on ASP NET CORE but ToList() works - Error "Sequence contains no elements." c# entity-framework-core linq. English (en). I found the issue. I get the list with a select that fails because a MAX() inside the select fails. Max() issue (Only happends with EntityFrameworkCore ): -> Stackoverflow: Max return value if empty query

Comments
  • I have found a way to back track. I will be using some kind of version control from now on. Still have no idea what this error means.
  • This! This solved it for me. Seems like a bug (?) in the way EF processes data annotations? Thank you for it, anyway!
  • This happens with [Column(TypeName = "decimal(8,2)")] as well.
  • #M. Mimpen what did you do with decimal to solve your issue ?
  • This also happens with [Column(TypeName="boolean")] ... change this to bit
  • received the same error on my fluent configuration file .HasColumnType("varchar(50)").IsOptional() threw an exception but .HasColumnType("varchar").IsOptional().HasMaxLength(50) fixed it
  • I tried this but the migration I scaffolded for step 1 gave the same error stackoverflow.com/q/29745049/150342