Why is Entity Framework missing the last s in a table that ends with 'Status' - entity-framework

This is a really weird error, I have looked online and can not see any obvious reasons why this is happening.
I am using Database First Entity Framework version 5 and have added 4 tables called:
WorkStatus
JobStatus
SubJobStatus
SubJobStageStatus
JobStatus, SubJobStatus and SubJobStageStatus each has a foreign key constraint to WorkStatus.
I have updated my edmx to include these tables but for some reason each table is missing the last s from the word Status. So the tables and their navigation properties are now called:
WorkStatu
JobStatu
SubJobStatu
SubJobStageStatu
Does anyone know why this happens?

"-Status" is being interpreted as a plural, and Entity Framework is being "helpful" by de-pluralizing.
For example, if you have a table called "Customers" EF will generate an entity called "Customer", which is in fact nicer in code:
var customer = new Customer();
It isn't working out so well in your case; your tables are already singular.
You can rename your tables to "-Statuses" or update the names in the designer or disable pluralization:
Under Tools > Options

Related

Update edmx after adding additional column to junction table

I'm using .Net 4.5, entity framework 5, database first. I have a junction (many-to-many) table in my database. For this example lets say the table is "StudentsCourses":
Students
-PkStudentId
-Name
Courses
-PkCourseId
-CourseNumber
StudentsCourses
-FkStudentId
-FkCourseId
This works just fine right now. The 'generate model from database' creates a Student entity with a navigation property to the Course entity. But here is where the trouble is:
I need to add another column to the StudentsCourses table. Lets just call this column "CourseYear". So our junction table would now look like this:
StudentsCourses
-FkStudentId
-FkCourseId
-CourseYear
So, I've added this column to the database and ran "Update Model from Database" on the edmx. I would expect to see an entity created for StudentCourses, with a navigation property to both Students and Courses. But no such entity is created. I still see the same two tables (Students & Courses) with the same navigation property as before.
I've done a lot of reading and researching, but haven't really come across a clear-cut answer. There is a wealth of information on code-first which I can't apply to my scenario. Is there a way to get what I'm after? Is it as simple as adding a PkId to the StudentCourses table? SQL Replication is preventing me from doing this. I would think the composite should suffice, but maybe EF needs a PK to do it's magic? I read a little bit about manually setting relationships, but could not find anything speaking to my particular situation. It could be that I am just missing a simple step in the process of updating the edmx from database. I've done this plenty of times when: adding new tables, adding columns, deleting columns, etc. I'm following the same steps as I always do, but maybe I need to do something different in this case?
Thanks ahead of time for any help. It is greatly appreciated. Please let me know if any more information would help.
From what I've gathered it appears as though EF will not generate a model for a table that doesn't have a Primary Key.
I'm a bit late for this, but you have the answer in this thread Updating Entity Framework Model after adding a field to a previous look up only table
As they say here, you have to delete the relationship between Students and Courses in the designer. Then update your model from the database, and make sure StudentsCourses table is checked in the Tables branch of the Add tab.

Why does entity framework skip one of my tables?

Entity framwork made a entity for each of my tables except for one, and I'm not sure why. I select it when i generate it from the database.
Here is my entity framework diagram, and the diagram in SQL:
http://imgur.com/a/zY17T
Notice how RecipeMeal is missing from entity framework. Does anyone have an idea why this might be happening?
RecipeMeal is supposed to store if a recipe is breakfast, lunch etc. It's not a column of Recipes because a recipe could be a lunch OR dinner recipe, as an example.
I am using EF 5.0
Thanks.
Entity Framework has built-in support for many-to-many relationships.
The table is exposed through the two ICollection<T> properties in Meal and Recipe.
I also found that if your table doesn't have a primary key it will also get skipped. One of my tables was just a summary table and didn't really need a primary key and it wouldn't be included in the reverse engineer. As soon as I added a primary key it was picked up.

Entity Framework Cardinality Issue on a 0...1 Association

I have database tables that look like this:
A Task can be mapped to a Module, or not mapped at all (0...1). I'm using Entity Framework database-first, and when I generated the model from the database, the Task entity came through with Modules as a collection (0 or more). So I opened up my EDMX and changed the "Modules" navigation property on Task to 0...1.
Now, when I attempt to compile, I get this error:
Error 3003: Problem in mapping fragments starting at line 1241:Given the cardinality of Association End Member Task, it should be mapped to key columns of the table TaskModule. Either fix the mapping or change the multiplicity of this end.
I don't understand what I need to do to fix this. I've looked at the association details and can't see the issue. I know I'm probably missing something stupid, but am totally stuck. Association properties:
Visual Studio 2010 SP1, Entity Framework 4.3.1.0, SQL Server 2008 R2.
One way to do this is to redefine the primary key for the TaskModule table. Instead of the primary key being (TaskId, ModuleName) it needs to be just (TaskId). Then do an update model from database and change any of the associations manually that didn't get picked up from that update.
Well your database schema is not correct with the description you give :
the TaskModule table implicates a many-to-many relationship, not a many-to-oneOrZero.
In edmx, many-to-many relation tables are not displayed, but they still exist in database.
So you should fix your database, or be happy with the relation proposed by EF !

Lack of a many-to-many linking table in EF 4.0 a bug or a feature?

I have a comment and a question. Entity Framework 4.0 does not show the linking table in a many-to-many relationship between two tables, such as shown in Northwind for “Order_Details”, a linking table between Orders and Products, if only two columns, both primary keys, are used in the linking table, as is often the case. So in Northwind if you use as primary keys both OrderID and ProductID in the Order_Details linking table between Orders and Products, for the many-to-many relationship, the linking table will not show up if only these two columns (primary keys) are present in Order_Details.
Consequently, you cannot Insert or Create in a many-to-many relationship linking table, because Entity Framework 4.0 does not show the linking table Order_Details nor does Intellisense show this linking table of the many to many relationship. How is one to then do an insert or update in the linking table if EF 4 does not show the hidden linking table? Arguments such as 'you must now start thinking in OOP' do not impress me. SQL has a certain structure and OOP is just an interface for it so we can use LINQ-to-entities rather than the clumsier SQL queries, IMO.
The trick to get around this bug was suggested for Silverlight here, http://forums.silverlight.net/t/159414.aspx/1 , and it works for web services and any other .NET solution: simply add, in your linking table, a dummy column of any type.
Now delete your original .edmx file, and rebuild a new one by generating it against the actual database.
Then intellisense shows the linking table, and then you can Insert / Create and do other normal oprations.
For example, Intellisense in EF 4.0 will now show the linking table Order_Details, and you can create or insert such as (partial fragment,omitting try/catch and any rollback options):
using (aDBEntity context = new aDBEntity())
Order_Details newOrdDetails = new Order_Details();
newOrdDetails.OrderID = //some number here
newOrdDetails.ProductID = //some number here
context.AddToOrder_Details(newOrdDetails);
context.SaveChanges();
Question: is this lack of showing a many-to-many linking table a bug or a feature of EF 4.0?
Personally, I think the linking table is not needed if you don't have any additional column other than two keys in it. I have never needed to access to the link table which is just used to define M2M relationship. I feel relaxed with adding relation between Foo and Bar by getting Foo (or Bar) first and use Foo.Bars.Add(sampleBar).
I think you answered your question. If you think OOP, this is a feature. If you want to have access to the link table (and you think you're doing it the right way), this is a lack of feature.

Entity framework - "Problem in mapping fragments"-error. Help me understand the explanations of this error

Error 3007: Problem in Mapping Fragments starting at lines 186, 205: Non-Primary-Key column(s) [WheelID] are being mapped in both fragments to different conceptual side properties - data inconsistency is possible because the corresponding conceptual side properties can be independently modified.
I found several places on the web describing this error, but I simply don't understand them. (confused smiley goes here)
One
Two
Three
Four
There is something pretty fundamental here, I must be missing. Can you explain it, so that I understand it? Maybe using my real life example below?
Foreign key 1:N Wheels.Id -> Slices.WheelId
I add them to entity framework, and WheelId is not visible in the Slices-entity.
Doing some workaround (deleting the relationship from the db before adding tables to EF - then re-creating it and updating EF) I managed to get the WheelId to stay in Slices, but then I get the error mentioned at the top.
Since Slices.WheelId is an FK, you cannot expose it in your client model, period. There are ways to get the value, though.
var wheelId = someSlice.Wheels.ID;
Update In EF 4 you can do this by using FK Associations instead of independent associations.
Try to remove foreign property column from Entity set using entity model design it will solve your problem
For example
We have two tables one is customer and other one is order, using entity model design we added association between customers and orders when we do this Ado.net entity framework i will add navigation properties to both below tables.
Like
Customer.Orders - Here order is list
Order.Customer
One - Many relation.
So we need to remove property from with name CustomerId[Foreign key column] from Order entity set.
For reference:
http://social.msdn.microsoft.com/forums/en-US/adodotnetentityframework/thread/2823634f-9dd1-4547-93b5-17bb8a882ac2/
I was able to overcome this problem by the following steps:
right click the designer window
Select 'update model from database'
Select Add AND make sure that the 'Include foreign key columns in the model' checkbox is selected.
click on Finish...
I had set foreign keys up in the database but framework still wasn't pulling them in correctly. So I tried to add the association myself. 
However, when I did this I would get a mapping error. It took me A WHILE but I figured out. What I did was set up the association using the entity toolbox association tool and then you have to double click on the association (1 to many) line and set the primary and foreign key there. Hopefully, this to help others who might have the same problem. I couldn't find the answer anywhere.
I had this problem for quite a different reason, and the message was slightly different; it didn't say "data inconsistency is possible because the corresponding conceptual side properties can be independently modified."
I have a table involved in my model with a binary column where I store image data. I only want this data returned when I need it (performance is a feature), so I split the table using a method similar to this. Later on, I added a property to that table, then updated the model from the database. The wizard added the property to both entity types that refer to the table with the added property. I had to delete it from one of them to solve the error.
I've had this happen because Entity Framework Update wizard mismapped some keys (or did not update?). As a result, some columns were mistakenly labeled as keys, while actual key columns were treated as plain columns.
The solution was to manually open EDMX file, find the entities, and update the keys.
Couldn't get any of the answer to work with EF6. The problem seems to be the framework doesn't import the foreign keys correctly as Associations. My solution was removing foreign keys from the tables, and then manually adding the associations using Entity Framework model, using the following steps: Entity Framework - Add Navigation Property Manually
For LinQ to Entities queries in EF1, my workaround for not having access to the foreign key as a property is with the following code, which does not produce a join query to the associated table:
dbContext.Table1s.FirstOrDefault(c => (int?)c.Table2.Id == null)
i.e, the generated SQL is:
...WHERE ([Extent1].[Table2Id] IS NULL)...
Solution is to allow deleting Rule = Cascade on Sql association.
Same thing as to be done on .edmx model, adding element to
association:
<Association Name="FK_Wheels_Slices">
<End Role="Wheels" Type= "your tipe here" Multiplicity="1">
<OnDelete Action="Cascade" />
</End>
</Association>
I had a table already mapped in EF. I added two more tables which had foreign keys in the previously added table. I then got the 3007 error.
To fix the error I deleted all three tables from the EDMX file, and then re-added them all at once together (via "Update Model from Database..."), instead of in stages.
I checked my Error List window and noticed I had errors in the model. Fixed them and all is well
in my case I solved this error by tick (include foreign key columns in the model)
- update Model from database
- tick (include foreign key columns in the model)
- finish