Questions tagged [entity-data-model]
14 questions
2
votes
1 answer
Entity Data Model Wizard Gets Exception When Trying to Add a New Oracle Connection
I'm trying to generate/update an edmx model from an oracle database and I need to create a new connection to that oracle database. When I click "Test Connection" it succeeds but when I click "OK" it gives the following error:
Operation is not valid…
Silmarie
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- 3
2
votes
1 answer
API to query your Entity Framework context's model?
I'm using EF code-first, and I'd like to identify, programatically, which properties are navigation properties, which are foreign keys, and which are Ids. Eg, in this classic Order/Item example;
public class Order
{
public int Id { get; set; }
…
Steve Cooper
- 20,542
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2
votes
0 answers
ADO.NET Entity Data Model vs DataSet vs Entity Framework?
So I know there are few ways to access data from the database.
I worked a bit with ADO.NET Entity Data Model, DataSet and Entity Framework. But still I can't quiet grasp what is what. I know the basic stuff about each of them.
So now I have a few…
TheNewGuy
- 49
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- 2
2
votes
1 answer
ADO.NET Entity Framework and ADO.NET Entity Data Model?
This is confusing me a bit... When people talk about ADO.NET Entity Framework are they actually talking about ADO.NET Entity Data Model?
TheNewGuy
- 49
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- 2
1
vote
1 answer
Visual Studio 2015 and Entity Data Model. Errors when rebuilding after uptating .edmx file
I have imported on VS 2015 a MVVM solution developed under older versions (2010).
I should to update an Entity Data Model, to add some fields to a table. So, I decided to modify the XML code (as I used to do in VS2010), and this works. But when I…
calacausi
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- 5
0
votes
1 answer
How do I map M:N relationship whose otherside is a weak entity?
I'm trying to map my ERD to a relational schema; one trouble I ran into is regarding the ENROLLS relationship which is M:N. For M:N in relational diagram, i know a separate table is made with the PKS from both sides. However, my other side is a weak…
S. Coughing
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- 11
0
votes
1 answer
Entity Framework database-first workflow designer failed
I am trying to create EDM using Entity Framework's database-first workflow designer. It fails right after starting running with error message
Object reference not set to an instance of an object
However it creates an .edmx model with just 2 files…
Alexey Pankratov
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- 4
0
votes
0 answers
Update model from Firebird database
I would like to update model from a Firebird database in Visual Studio. I followed this tutorial: https://www.ibprovider.com/eng/documentation/connection_to_firebird_in_visual_studio_2017_via_ddex_provider.html
In Server Explorer, I successfully…
Tippi
- 15
- 4
0
votes
1 answer
Data Model - Regions and Countries
We have divided the world map into 6 regions and each region will have list of countries.
We have products which we mark to make sure which are all countries has it.
How we model this as we have more than 200 countries and marking this country list…
P S
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- 1
0
votes
1 answer
While trying to create entity data model, I get authorization exception
I set up my visual studio to always run as administrator.
When I create a new Entity Data Model, and try to point to the data source to a specific database, I get the error "Login failed. Log in is from an untrusted domain...."
I think that since I…
HillOfBeans
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0
votes
1 answer
Could not update model from database?
Visual studio get stuck when I update my Entity Data Model from database and it takes long time to update the EDM from local DB. What should I do to avoid this problem ?
I use VS 2013
Ravi Rajindu
- 380
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0
votes
1 answer
Visual Studio 2015 Add new data source wizard missing entity data model
I have installed Visual Studio 2015 & SQL Server 2014.
When I try to add an Entity Data Model in wizards window Choose a Database Model, I have only Dataset as a option.
So, I've tried next thing - right click on a project name:
-> add -> new item…
GMuser
- 11
- 4
-1
votes
1 answer
Getting Error While Setting The data to Sql Db, Saying Cannot set the Value of Created at with Null
I am Creating a table in SSMS with the Columns required for the Table and also with the Entitydata mandatory fields Like Id, CreatedAt, UpdatedAt, Version, Deleted.
And while setting the data through my application I am having Issue Like:
Cannot…
Amitesh
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-1
votes
1 answer
Relational model to entity relationship - Database
I know it is possible to convert the entity relationship to a relational model but is it possible to convert the relational model to entity relationship using the same rules? I have looked for it in the internet but people always convert from ER to…
Juan Manuel Amoros
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