#entity-framework-4

Fix: The specified named connection is either not found in the configuration, not intended to be used with the EntityClient provider, or not valid #answer #solution #computers

The specified named connection is either not found in the configuration, not intended to be used with the EntityClient provider, or not valid

i have a one entity framework object and when i add it to my project, the connectionstring is add to app.config in connectionstring section, but when i want create new entitycontext and use this connectionstring, this error is appear

Answer [by Morteza…

How to: There is already an open DataReader associated with this Command which must be closed first #solution #it #computers

There is already an open DataReader associated with this Command which must be closed first

I have this query and I get the error in this function:

var accounts = from account in context.Accounts from guranteer in account.Gurantors select new AccountsReport { CreditRegistryId = account.CreditRegistryId, AccountNumber = account.AccountNo, DateOpened = account.DateOpened, }; return…

How to: Entity Framework 4 / POCO – Where to start? #solution #computers #development

Entity Framework 4 / POCO – Where to start?

I’ve been programming for a while and have used LINQ-To-SQL and LINQ-To-Entities before (although when using entities it has been on a Entity/Table 1-1 relationship – ie not much different than L2SQL)

I’ve been doing a lot of reading about Inversion of Control, Unit of Work, POCO and repository patterns and would like to use this methodology in my new…

How to: Entity Framework 4 – AddObject vs Attach

Entity Framework 4 – AddObject vs Attach

I have been working with Entity Framework 4 recently, and am slightly confused as to when to use ObjectSet.Attach, and ObjectSet.AddObject.

From my understanding:

Use “Attach” when an Entity already exists in the system

Use “AddObject” when creating a brand new Entity

So, if i’m creating a new Person, i do this.

var ctx = new MyEntities(); var newPerson =…

How to: What effect(s) can the virtual keyword have in Entity Framework 4.1 POCO Code First?

What effect(s) can the virtual keyword have in Entity Framework 4.1 POCO Code First?

The virtual keyword has an effect when used on properties in EF Code First. Can someone describe all its ramifications in different situations?

For instance, I know it can control lazy loadingif you use the virtual keyword on an ICollection/one-to-many relationship property, it will be lazy-loaded by default,…

How to: The specified named connection is either not found in the configuration, not intended to be used with the EntityClient provider, or not valid

The specified named connection is either not found in the configuration, not intended to be used with the EntityClient provider, or not valid

i have a one entity framework object and when i add it to my project, the connectionstring is add to app.config in connectionstring section, but when i want create new entitycontext and use this connectionstring, this error is appear

Answer: The specified…

How to: There is already an open DataReader associated with this Command which must be closed first

There is already an open DataReader associated with this Command which must be closed first

I have this query and I get the error in this function:

var accounts = from account in context.Accounts from guranteer in account.Gurantors select new AccountsReport { CreditRegistryId = account.CreditRegistryId, AccountNumber = account.AccountNo, DateOpened = account.DateOpened, }; return…

How to: Entity Framework 4 / POCO – Where to start?

Entity Framework 4 / POCO – Where to start?

I’ve been programming for a while and have used LINQ-To-SQL and LINQ-To-Entities before (although when using entities it has been on a Entity/Table 1-1 relationship – ie not much different than L2SQL)

I’ve been doing a lot of reading about Inversion of Control, Unit of Work, POCO and repository patterns and would like to use this methodology in my new…