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Entity Framework 6.0

EF6.0

Great Reads

Adding INotifyPropertyChanged to Entity Framework Classes

by MarkLTX

Automatically implement INotifyPropertyChanged for every property in Entity Framework 6.0 entity classes

Manage Entity Framework Code First in Real Time Projects

by DiponRoy

How to manage Entity Framework Code First in Real Time Projects

Entity Framework Introduction Using C# - Part One

by Emiliano Musso

In this article, we will see how to use entity framework in our Applications, developed through the various languages that Visual Studio allows us to use. The examples in this article and probably in the next, will be C # used under WinForms, but - as mentioned - this choice is not going to affect a

Finding Non-disposed Contexts in Entity Framework 6.x Applications

by Vahid_N

It's easy to forget not disposing object contexts, which leads to memory leaks and also leaves too many related connection objects not disposed as well.

Latest Articles

EF6 Migrations and TimeStamp Bug with CodeFirst

by Herman.Instance

Migrations does not apply to T-SQL rules for ALTER TABLE ALTER COLUMN

Learning Entity Framework (Day 2): Code First Approach and Migrations in Microsoft .NET Entity Framework

by Akhil Mittal

Code First Approach and Migrations in Microsoft .NET Entity Framework

CRUD Operation in ASP.NET Core Web API with Entity Framework Core

by MukeshKumarTech

This article will explain how to perform CRUD (Create, Read, Update and Delete) operations in ASP.NET Core Web API using Entity Framework Core.

ASP.NET MVC 5: Building Your First Web Application - Part 1

by Vincent Maverick Durano

This article is part 1 of the series for building a simple web application in ASP.NET MVC 5.

All Articles

Entity Framework 6.0

Import from excel to DB and the display them from DB using EF in MVC

3 Oct 2018 by #realJSOP

If it doesn't have to be a real-time process, you could create an SSIS package to import the uploaded file, create a SQL server job to run the package, schedule that job to run every N minutes, and simply let the user hit refresh on the web site whenever he wants. I know it sounds like a lot of...

Why VIEW data don't show correctly in gridview ?

3 Apr 2019 by #realJSOP

0) Your linq query makes no sense because EVERY day is between the first/last day of its month. Maybe you meant to compare just the month? (We can't see what the vars LastDayofMonth and FirstDayOfMonth are, but I assumed they're a datetime.) Maybe better names would be StartDate and EndDate? 1)...

entity-framework

Add parent and child together by .NET EF6 code first

2 Dec 2021 by 4L4K1

according to the code in what I have tried section BuySellHouse is parent EstateImages is child I tried to create a 1 to 0/1 relationship. I am not sure I did it correctly inserting parent with child by code like this gives me an error ...

I need to use left outer join in entity framework method based

28 Jul 2014 by _Amy

I'm adding few more links in above solution:MSDN : join clause (C# Reference)[^]SQL Joins with C# LINQ[^]C# Join[^]--Amy

entity-framework

Best way to organize WEB API method for following scenario

22 Feb 2015 by _Maxxx_

I think, to me, the Person controller needs to handle this.A Person needs to know about a Phone - but a Phone needs no knowledge of a Person.So your phone controller shouldn't need to know about Person at all.

How Can I Refresh My Context Of Entity Framework

31 May 2014 by aanbidmij

Hello everyone,I have a small program (multi user).When I run 2 sessions of my program and in session 1 I do an update of the data, I can't see the updated data in session 2. However the updated data is stored correctly in the database.When I do an insert in session 1, I see the...

MVC 4.5 with entity framework

18 Aug 2014 by Aashish vermaa

Hello,I am working on project in which we are going to use MVC 4.5 and Entity Framework6.There are some doubts in my mind that are; 1. Can we use stored Procedure with Entity framework. Because there is a scenario where we insert and update data in multiple tables on single...

How do I...Get the list with relational values and display

29 Apr 2015 by Abdul Shakoor p

I have Models "Category" & "SubCategory". CategoryID is foreign key in SubCategory Table. I need to fetch all the Category and related SubCategories and bind in an Accordion list.This is my code :

How to send data as either 0 or 1 to database from MVC?

22 Apr 2015 by Abhinav S

You can use tinyint[^] or char[^] to store 0 and 1. An alternate could also be to use a bit[^] type.Here are some examples on create a dropdownlist in a view - DropDownList / Basic usage [^]DropDownListFor with ASP.NET MVC[^]

How to fix EF code first approach on exisitng database.

19 Sep 2018 by AbhishekDotNet

Hi,I have a created two separate C# web application using EF6 (one with Database First and other with Code First approach). everything is going on smoothly but after sometime it is required to merge both.After merging , Database is same for Code First Approach.Initial I was using...

SQL-Server-2012

Unknown Class Dynamically Generated at runtime for Entity Framework, WCF OData and dynamic client consumption

7 Nov 2014 by Adriaan Booysen

An example of a nearly complete unknown type being used accross EF, WCF and consumed client side

How Do I Send Android Data To .Net Database.

21 Apr 2015 by Afzaal Ahmad Zeeshan

Since you are going to use Web API, why are you confusing yourself to use native .NET framework at all?You should build a simple Android application with default WebView control added to it. Which can then target your API. Do you know much about ASP.NET Web API[^]? If not then please learn...

How to use Collection Functions like Intersect without impacting performance ?

28 Jun 2014 by Ahmad_kelany

Hello everyone,Short Story : UP2Entities up2ent = new UP2Entities();List items = new List(); items = up2ent.ViewAllItems.ToList(); lstYesTag = pnlTags.Children.OfType().Where(l1 => ((SolidColorBrush)l1.Background).Color ==...

work with SQL Function in Entity Freamwork ?

6 Feb 2015 by Ahmed Amin

Hi01. i have create an sql function in my database that take to Date params and get data from 5 tables02. after that add it to project as entity framework from database and the code generated is: [DbFunction("Dr_EmploEntities", "SelectEmployee")] public virtual...

What scenario using code first or entity framework

13 Jan 2017 by ahmed_sa

I need to build web site by .net web technology asp.net mvc USING C#But i confuse What is best for build Web site Implementation by MVCUsing Entity framework(build database and create modules automatic by EF)ORImplementing web site by using Code First ?What I have...

entity-framework

System.Reflection.TargetInvoca...

14 May 2015 by Akalanka Kasun

I got following exception when updating data from my database tableException : System.Reflection.TargetInvocationException' occurred in EntityFramework.SqlServer.dll but was not handled in user codeHere My Code private bool updateUser(UserCategoryModel userCategory) { using...

Not generated base query entity framework 6

14 May 2015 by Akalanka Kasun

using (var db = new EntityContext()) { var count=db.UserCategories.Where(a => a.UserName == userName).Count(); return count> 0; }Here when database initialize UserCategories table doesn't generate base query?

Learning Entity Framework (Day 2): Code First Approach and Migrations in Microsoft .NET Entity Framework

28 Sep 2018 by Akhil Mittal

Code First Approach and Migrations in Microsoft .NET Entity Framework

Is stored procedure with Entity framework good design or have to write direct queries on front end (no stored procedure)

15 Jul 2015 by Alexandru Lungu

Check Stored procedure vs standard query. It should answer your question.

Entity framework 6 save from list

19 May 2019 by Ameer Adel Al-Zubaidy

Hello I am on my first EF6 project and I have couple of questions Project outlines Property (Building) have Rooms A Room have list of criteria or rating Each criteria own a set of values i.e. Property (Building) A have Room 1 Each room have bunch of values Value a 0-1...

Entity framework 6 save from list

19 May 2019 by Ameer Adel Al-Zubaidy

Right first of all sorry for the rough English, I am a mess right now the solution is as follows: Loop through the existing Main categories (Property(Building)) for Property.Count Property[i].Rooms = inProperty[i].Rooms So on and so forth for the other nested lists ...

I am new to LINQ to entity how can I create a dynamic query

24 May 2014 by Andreas Gieriet

You might check out Invent your own Dynamic LINQ parser[^]. I wrote that parser a while ago to create predicates suitable for LINQ-to-Object queries.CheersAndi

How to solve System.TypeInitializationException with Entity Framework 6

4 Jul 2018 by Andrew797

I started developing an MVC app on my laptop, which was running VS2013, and SQL server 2008 R2. I copied this project over to my desktop computer running Visual Studio 2013, SQL server 2012 Developer Edition.When I run this MVC app from my Desktop, I get the following error on the line...

How do I used Entity framework effectively on a windows service

28 May 2015 by Andy Lanng

A1: I don't know what "longer lifetime" meansA2: Entity framework is thread safeA3: Use transaction scope*B1: Only when you use itB2: Use transaction scope*B3: Use transaction scope carefully*Entity framework is thread safe. avoid using the same instance of the DBConext to...

Entity relationships design

23 Jun 2015 by Andy Lanng

For Larger projects that depend on an efficient db design:(this is 90% of the dbs I have written)I recommend pen and paper :SThe process good of DB design goes through several iterations of normalization and de-normalization. I find it useful to organize my db way before I start...

How do I fetch sql data (including linked data 1-*) using entity framework

21 Aug 2015 by Andy Lanng

Hi,I am connected to my db via LINQ to SQL dbml objects. When I search for customers I need to get several linked tables too.These include things like Payment Details, contact history, claim history etc...I use paging so my data sets won't ever be very big. I would like to get all...

How do I fetch sql data (including linked data 1-*) using entity framework

12 Oct 2015 by Andy Lanng

This answered this question:Quote: Richard Deeming at 21-Aug-15 11:20amAre you looking for the Include method[^]?Entity Framework : Loading Related Entities[^]Loading Related Entities with Entity Framework - A Beginner's Primer[^]

How Can I Use Where Condition Inside Include In Entity Framework

4 Mar 2015 by anilsarapati

Hi All,I am trying to use where condition inside include in an entity framework query as below.var results = _courseService.QueryCourses() .Include(x => x.Language) .Include(x => x.Versions.Where(u=>u.Overwrite==null).Select(y => y.Language)) ...

I want to use GroupBy for DateTime Without (Hour and Minute and Second)

8 Sep 2014 by Animesh Datta

Try this wayList = dbcontext.content.ToList().Where(u =>(Convert.ToDateTime(u.Date).Month==M_no) || (Convert.ToDateTime(u.Date).Year==year_no) || (Convert.ToDateTime(u.Date).Day==day_no)).ToList(); example will demonstrate the properties .System.DateTime moment = new...

entity-framework

Entity Framework Code First Entities and entity relationships

23 Sep 2015 by Arian Celina

This article is a part of a multi-post article on Entity Framework Code First for web applications: Entity Framework Code First Entities and entity relationships Entity Framework Data Context Entity Framework Migrations and Data seeding It is not very often that I see web development tutorials

entity-framework

What you need to know about Entity Framework Data Context

25 Sep 2015 by Arian Celina

This article is a part of a multi-post article on Entity Framework Code First for web applications: Entity Framework Code First Entities and entity relationships What do you need to know about Entity Framework Data Context Entity Framework Migrations and Data seeding This article is the second

entity-framework

What Wrong With This EF Code First Model..?

3 Mar 2015 by Arif H Shigri

This Is The Exception Em Recieving."The property 'MeterID' cannot be configured as a navigation property. The property must be a valid entity type and the property should have a non-abstract getter and setter. For collection properties the type must implement ICollection where T is a valid...

How to pass n number of parameters to stored procedure(sp) in entity framework

4 Mar 2016 by AshishvermaMCA

How to pass n number of parameters to Stored Procedure(SP) in Entity Framework What I have tried:I have not any idea because in EF dynamically mapping is performed.So how can pass n- number of parameters in SP

Relationships between Tables Using Entity Framework

23 Aug 2015 by Avenger1

I'm using Entity Framework for my database in asp.net but when my database is on localhost it automatically add the tables and relationships but after I uploaded my database to host and I tried to use it in model.edmx it add tables without relationships.I tried to add relationships with the...

What is the reference for .Create() method, Entity Framework 6

19 Apr 2014 by Barcelonista Naser

Dear All.I am trying to build a User authentication in ASP.Net MVC4 from a tutorial. I am already done with 80 % of the project but at the end i have faced with a problem. I couldn't get a clue even googling for an hour. I have a user control just like below. using System;using...

Use previous version of libraries on NuGet?

14 Sep 2014 by Bastien Vandamme

I'm building a project with Entity Framework and MySQL. For compatibility reason I need to use Entity Framework 5. I did a little mistake and updated my Entity Framework to version 6.1.1 with nuget package manager. I would like to uninstall this version 6.1.1 to use the version 5. Is it possible?

Which config file Entity Framework is using

15 Sep 2014 by Bastien Vandamme

I have a solution with 3 projects. - one for Entity framework that contains my edmx diagram (App.Config) - one for my core business (App.Config) - and one for my web API (Web.Config)When I publish my project on my hosting service or my personal server I also...

Using FakeItEasy with Entity Framework 6

7 Dec 2017 by Ben Hall (failingfast.io)

How to use FakeItEasy with Entity Framework 6

How Do I Can Call Post Method From Direct From Url?

9 Sep 2014 by Bhagyashree Chaudhari - Member 10473634

Good Afternoon ,I want to make web api , which will be in my existing " WEB FORM Application " and i want to GET , POST my data in database ( POSTGRESQL ).First , when user click on my webapi url , it will ask for client certificate if its valid (till here done ) then user can GET and POST...

Reuse EF , change POCO classes to point to views

24 Feb 2015 by Biswabid Rath

I want to reuse an existing project code. I have all the POCO classes(replica of tables) available with me from the old project which is attached to DBCOntext also. However in my new project my DB structure is different. I am planing to replace the old POCO classes with new ones with same...

which approaches is best to manipulate data for MVC project?

2 Nov 2014 by christhuxavier

I am going to create MVC base project with EnityFramework.But Enity Framework has three approaches as we know as,1)Schema based approach2)Model based approach3)Code first approach.which approaches is best to manipulate data for MVC project?

Should I use an existing complex view or recreate the query in my application?

17 Apr 2019 by Christian Graus

Presumably you created those views to simply access to sets of data that resolve specific problems in your domain. So, keep them.

How to make user create on system only once ?

25 Nov 2017 by Code Atom

I m facing a problem, I have API that sends a request with a list of email addresses, now what system does it check each email address from the database, if it exists then it ok we use userid else we create a new user. The problem arises when we send multiple requests with the same list of...

Difference between ICollection<SomeModel> vs List<SomeModel>

25 Nov 2014 by CPallini

Please note, your code wouldn't compile (you need to give a name to your ICollection or List property).In the first case, e.g.public class Customer{public int Id { get; set; }public int Name{ get; set; }public ICollection ProdColl{ get ; set ;}}You may use any of the...

SQL Dependency using Entity Framework in WPF

6 Apr 2018 by CyberMakarov007

SQL table dependency with entity framework in WPF

entity-framework

How Can I Refresh My Context Of Entity Framework

31 May 2014 by DamithSL

you can use Refresh method of the context or dispose the old context and create again. But if you need to refresh only when the context change and it need to be happen automatically whenever database changed. Then you can try below article with SQL Server Service Broker.AutoRefresh Entity...

How to do return array or list<string> Entity Framework ?

17 May 2015 by DamithSL

you have .FirstOrDefault(); at the end of your c# statement and it will give only single item or null value as result. if you need array or list, use ToList or ToArray methods var obj= db.Database.SqlQuery("EXEC GET_GROUP_PERMIT @GID", idParam).ToList();return...

stored-procedure

ERP INFRASTRUCTURE

15 Dec 2015 by databaseobjectmodel

A sample infrastructure project such as erp, mrp, crm, admin panel.

.NET-Compiler-Platform

Entity Framework 6 - Default Values are allowed only for non-spatial primitive types.

14 Apr 2014 by Dave Kreskowiak

The first question is why are you using "Type"? That is not a good name to use as it is a class name that is used by .NET and is going to lead to confusion in the code.I think your Type should become MarketType, and could also be the name of your Enum. public enum MarketType { ...

How Can I Refresh My Context Of Entity Framework

31 May 2014 by Dave Kreskowiak

If you're creating an instance of the context and keeping it alive for the lifetime of the application, you're doing it wrong.Create a context when you need to do a query and Dispose it when you're done. This way, you don't have to "refresh" it. It'll pickup the new data when ever you do...

Reuse EF , change POCO classes to point to views

24 Feb 2015 by Dave Kreskowiak

OK. Weird. You do realize you won't be able to write anything back to the database, correct?If you had, in your original solution, all of the EF code in a seperate project(s), completely seperate from the application code, you wouldn't have to recreate everything in your new solution. You...

What Wrong With This EF Code First Model..?

3 Mar 2015 by Dave Kreskowiak

It appears that your class should look like this:public class DomesticQuater { public int ID { get; set; } public Int64 QuaterNo { get; set; } public String QuaterType { get; set; } public int Block { get; set; } public String Area { get; set;...

Entity Framework. Get entity with a part of properties filled

6 Mar 2015 by Dave Kreskowiak

You don't. In EF you only get the entire entity stored in the database re-hydrated in the DbContext tacker.You can use projection to get just the properties you need copied into another object, but the database is still going to return the entire entity record and the DbContext is still...

How Do I Update Record Using Ef

14 Nov 2015 by Dave Kreskowiak

I SERIOUSLY recommend you get this book[^] and work through it. There's a ton of concepts you're missing as evidenced by your code and you're not going to learn them in a forum like this.Your code doesn't make any sense at all and your variable names need to be redone to make them meaningful...

Using SQL 2016 temporal tables with EF6, many to many relationships

10 May 2016 by Dave Kreskowiak

Temporal tables are not supported by EF6 and is not in EF Core 1.0 (what was EF7) since EF Core 1 is a complete rewrite from the ground up to make it platform independent. It is a current feature request and is being evaluated, though don't hold out for it to show up any time soon.

entity-framework

How to call async query in EF 6.0

27 Nov 2016 by Dave Kreskowiak

Your code is essentially single threaded. You've got 2 threads, but one is completely blocked waiting on the other. In any case, putting the LoadData code on a background thread, since it's the only thing you're doing, is no different than if you completely skipped all the Task/async/await...

What scenario using code first or entity framework

13 Jan 2017 by Dave Kreskowiak

Code First is a mode that Entity Framework works in. It is something to implement a web site. Entity Framework is an Object Relational Mapping tool. It automates a lot of the work to save data model objects to a database and reconstitute them back into objects from the database.Entity...

entity-framework

EF6 mapping results in strange update query

17 Aug 2018 by Dave Kreskowiak

You never gave any details about your database schema as coded in EF, so this is just a guess. What you're seeing is the expected behavior. You are NOT supposed to make any changes to a column tagged [Timestamp] in EF. Timestamp fields are entirely managed by EF. They are used to manage...

How to use repository pattern and unit of work for bulk insert with EF and give more performance?

2 May 2019 by Dave Kreskowiak

You can't really improve the performance using plain vanilla EF. No matter what you do, EF is always going to do one INSERT at a time for each item you're adding. There's no way to speed that up. I would suggest stepping outside EF for this and using the SqlBulkCopy[^] class instead. You're...

Can I use code first & database first in the same project?

6 Jun 2020 by Dave Kreskowiak

No. You can use one or other, not both in the same project. For a new project using Code First, EF will automatically create the tables for you from the DbSet entries in your DbContext implementation.

Performance Issue between Stored Procedure and EF Code First

27 Dec 2014 by deelll

If I want to retrieve a list of data and display it by using EF code first (http://msdn.microsoft.com/en-in/data/dn468673[^]) or stored procedure (http://msdn.microsoft.com/en-us/data/jj592907.aspx[^]), which of them has the shortest time to retrieve it?

Maintaining concurrency with database while using Entity Framework

1 Dec 2014 by Dexter11

I have just started with tutorials on Entity Framework(version 6) and also used it in one of my small project.There are few questions lingering in my mind...does the model in entity framework is auto updated? what if i am changing datatype for any column in database or adding new column...also...

Redis second level caching with entity framework 6

27 Aug 2015 by Dharma M

Hello Friends,I am new to redis caching. I want to cache our entity framework(database-first) object with redis cache as a second level and need to consume it from client. Please share how can I implement this?Regards,Dharma

Custom Seed Serializer for Entity Framework Code First C#

11 Jun 2014 by DiponRoy

Custom Seed Serializer for Entity Framework Code First C#

Manage Entity Framework Code First in Real Time Projects

28 Jul 2014 by DiponRoy

How to manage Entity Framework Code First in Real Time Projects

project-management

Create Primary Key using Entity Framework Code First

4 Sep 2014 by Dukhabandhu Sahoo

Explore the Entity Framework Code First convention and configuration for creating primary key

SQL-Server-2008R2

entity-framework

Use of Database.SetInitializer() Method in Code First

3 Sep 2014 by Dukhabandhu Sahoo

The use of different Database initializer options in Entity Framework Code First

entity-framework

Optimistic Concurrency in Entity Framework Code First

1 Oct 2014 by Dukhabandhu Sahoo

Handle optimistic concurrency using Entity Framework Code First.

SQL-Server-2008R2

Exclude Type from the Model in Entity Framework Code First

12 Oct 2014 by Dukhabandhu Sahoo

Know how to exclude types from the Model in Entity Framework Code First

entity-framework

Property Mapping in Entity Framework Code First

14 Oct 2014 by Dukhabandhu Sahoo

Learn how property is automatically mapped to column and how to manage it in entity framework code first.

entity-framework

Easy application to detect and recognize faces with EmugCV

7 Sep 2016 by Emanuel Santos

In this article i will show how to create a basic application to detect and recognize faces using EmugCV.

entity-framework

Entity Framework Introduction Using C# - Part One

10 Jun 2016 by Emiliano Musso

In this article, we will see how to use entity framework in our Applications, developed through the various languages that Visual Studio allows us to use. The examples in this article and probably in the next, will be C # used under WinForms, but - as mentioned - this choice is not going to affect a

entity-framework

Generic dbset<T> table name property

10 Jun 2020 by Enobong Adahada

Please how do I assign table name to generic DBSet base on Model? I want to create a table for every registered user, using their userId and the table name in EF6. public class ContactModel { [Key] [Required] ...

Need some suggestions on using ADO.NET or EF with LINQ

16 May 2016 by Eswara Palachooru

Hi Folks, we have application with Asp.Net 2.0 and SQL server Database and every month we save 2 lakhs transactions in one of my database table. In this table we have column with datatype as Text(where i can have huge data as string). Now i want to implement same application with...

SQL-Server-2008R2

Entity relationships design

23 Jun 2015 by F-ES Sitecore

Code first is better when you want to write code and have a database generated that reflects that code. Database first is better when you want to design the database yourself and have the code reflect that database. So if comes down to how particular you are about the database and how...

Need some suggestions on using ADO.NET or EF with LINQ

16 May 2016 by F-ES Sitecore

Google "entity framework vs ado.net" to see the pros and cons of both and decide which one meets your requirements. If raw speed is a factor you may err toward ado.net, but if your code is more complex you might prefer the simplicity of EF.

SQL-Server-2008R2

Lazy loading unacceptable behavior when using tolist() or load()

8 Mar 2017 by F-ES Sitecore

Disabling lazy loading doesn't stop related data loading, it stops it being loaded on-demand, so instead it is loaded right away. You might be better using the "Include" feature to dictate what data is lazy-loaded or not on a per-case basis. It will make it explicit what is being lazy loaded...

entity-framework

Collection was modified; enumeration operation may not execute. At foreach

7 Nov 2019 by F-ES Sitecore

Rather than executing account_Funds.Remove(f); keep a collection of all the items you want to remove; var toRemove = new List(); foreach (account_funds f in account_Funds) { if (trsBalance(f.accfunds_ID) == 0) { toRemove.Add(f); } } after...

How to update an entity with a collection of abstract types by using GraphDiff?

17 Jun 2015 by fairfriend

I have some models:public class RootEntity{ public int Id {get; set;} public virtual ICollection CollectionA {get; set;}}public abstract class AbstractEntity{ public int Id {get; set;}}public class DerivedEntityA : AbstractEntity{ ...

How to pass n number of parameters to stored procedure(sp) in entity framework

4 Mar 2016 by Frank Kerrigan

Pass raw SQL to EF[Entity Framework Raw SQL Queries[^]]

Dynamically generated lambda giving different result than regular lambda

16 Oct 2014 by GateKeeper22

I am have a problem with Dynamically generated compared to a regular lambda expression in code. Below is the code that I use to generate a dynamic lambda.Dynamic Lambdavar parameterExp = Expression.Parameter(typeof(T), "x");var propertyExp = Expression.Property(parameterExp,...

How Do I Fix It? The Provider Did Not Return A Providermanifest Instance In Vs 2013 And Entityframework 6

24 May 2015 by gaurav.s23

The metadata specified in the connection string could not be loadedConsider rebuilding the web project to build assemblies that maycontain metadata. The following error(s) occurred: The provider did not return a ProviderManifest instanceDo let me know if you know the solution.

How Do I Fix It? The Provider Did Not Return A Providermanifest Instance In Vs 2013 And Entityframework 6

24 May 2015 by gaurav.s23

1.go where you project is located(open Solution explorer. right click on solution and click on "Open Folder in file explorer")2.open EDMX file with notepad and change ProviderManifestToken="2012" to ProviderManifestToken="2008". save it3.build your solutionIts fixed.

How to Insert Records into many to many code first Approch

28 Dec 2014 by George Jonsson

This part of the code will give you this problemif (john.courses == null){ john.courses.Add(stoptalk); john.courses.Add(rails); db.Persons.Add(john); db.SaveChanges();}because if john.courses == null is true, the Add operation cannot be executed as no instance of...

How do I convert an integer to string to delete an entity in wpf

2 Jan 2015 by Gerhard_Louis

First time using Entity Framework 6 with WPF.I created a sample database to get familiar with WPF and Entity Framework.How do I delete a selected entity This is my codenamespace RubyTime.Pages{ public partial class Home : UserControl { private...

Insert data into DB from EF using composite key (primary)

18 Jul 2018 by Gerry Schmitz

A table cannot have more than one "primary key". EF can only recognize one primary key; either a single value or a compound key. Anything else would be a "secondary key / index"

Creating composite key with multiple foreign keys from same table EF code first

27 Apr 2019 by Gerry Schmitz

You have a one-to-one relationship according to you classes. Entity Framework – mapping references with composite keys | Feb dev[^] c# - Entity Framework Code First One to One relationship on composite key - Stack Overflow[^]

entity-framework

How to solve the problem of row repetition in this query

25 Apr 2020 by Gerry Schmitz

You're probably missing part of the "data" story and overriding a (duplicate) "key" with the IDENTITY function you're triggering with the "Key property".

entity-framework

Cannot capture datagrid collectionviewsource insert/delete row

12 Sep 2020 by Gerry Schmitz

Too much "coupling". The Observable Collection doesn't interact with the data context. You add event handlers to the OC (i.e. CollectionChanged) that interact with the data context. The entities in the OC should be "detached" from the DbContext...

EF6 order the results based on custom values

13 Sep 2020 by Gerry Schmitz

...OrderBy( o => switch( o.Status ) { case "Accepted": return 1; case "Pending": return 2; ... default: return 6; } ) .ThenBy ... etc.

Expression #6 select list is not in group by clause and contains nonaggregated column

26 Feb 2019 by Golden Basim

i created this view to calculate the total stocks of every item in every store as : CREATE OR REPLACE VIEW `view_items_stocks_smallest_unit_prices_noserials` as SELECT items.stitems_ID, items.stitems_Status, items.stitems_Name, items.stitems_Type, ...

Why VIEW data don't show correctly in gridview ?

4 Apr 2019 by Golden Basim

hi, i have MySQL VIEW : (4 record) sDate , Count , Amount 2019-04-01, 2, 600.0000 2019-04-02, 1, 4000.0000 2019-04-03, 2, 1400.0000 2019-04-04, 1, 3500.0000 i try to show this data in Gridview using EF6 var Purchases = DB1.view_purchases_amount_per_day.Where(x => x.sDate >= FirstDayOfMonth...

entity-framework

How to use stored procedure with EF6 ?

15 Apr 2019 by Golden Basim

hi, i created this view : CREATE OR REPLACE VIEW `view_items_accounts_tree_with_date` as SELECT Acitems.accitem_AccID, acc.accdet_Cat, acc.accdet_AccountCode, CONCAT_WS(' - ', acc.accdet_AccountCode,...

Dataretrievalexception: ambiguous match found.

15 Apr 2019 by Golden Basim

i try to show xtrareport , this report was binding to SP using Framework, but this error appear during creating document . report.CreateDocument(true); DataRetrievalException: خطأ عند محاولة ملء مصدر البيانات. تم طرح الاستثناء التالي: Ambiguous match found. this line "خطأ عند محاولة ملء...

Collection was modified; enumeration operation may not execute. At foreach

8 Nov 2019 by Golden Basim

i try to fetch the data (funds data) and filter the results with its balance but this error appear : System.InvalidOperationException: 'Collection was modified; enumeration operation may not execute.' at foreach (account_funds f in account_Funds) What I have tried: public...

How to insert this datetime value to DB using EF 31/12/2021 11:59:59 PM (end of the day in the year)

9 May 2020 by Golden Basim

how to insert this datetime value to DB using EF 31/12/2021 11:59:59 PM (end of the day in the year) 1- i created this field fiscal_year_end and its datatype is DATETIME. 2- now i trying to update the record with the value fiscal_year_endvar DB1...

Why some times this error happens "failed to connect to the database" with EF query?

3 Jun 2020 by Golden Basim

hi, some times (5-10%) when i try to execute EF Query this error appear : System.Exception: خطأ عند محاولة ملء مصدر البيانات. تم طرح الاستثناء التالي: Failed to connect to the database. To learn more, see the exception details. Exception...

EF6 the supplied connection is not valid because it contains insufficient mapping or metadata information.

5 Jun 2020 by Golden Basim

hi, based of my previous Question answers. and 2 day of search i decide to change my old approach that i use for setting a custom connection parameters. but i still have some issues, i preferred to create separated question because i thing it...

entity-framework

Can I use code first & database first in the same project?

6 Jun 2020 by Golden Basim

hi, i created new project C# & EF6 (Database First), but after some times i need to update the tables ( add new tables , Fields , delete Fields) What I have tried: in this time i use MySQL Query to do that , but i ask if there are any method...

EF6 order the results based on custom values

13 Sep 2020 by Golden Basim

hi, my project was created using c# & entity framwork 6 i have this table (entries) that have status filed the status filed will fill with one of this values : Pending,Accepted,Rejected,Delayed,Completed i want to retrieve all the record sorted...