Entity Framework "Invalid object name 'Item_id'" - entity-framework

I have a solution that has spontaneously started generating the error "Invalid object name 'Item_id'". I have searched for this but all answers seem related to code first issues around pluralization; my project is database first.
The context is that there is a Purchase with a collection of ItemPurchaseLines which are linked to Items. The error occurs when a new purchase is generated, this generates new ItemPurchaseLines and either links them to existing Items or generates new Items. The mapping between ItemPurchaseLines and Items is via a foreign key on Item_Id to Id respectively.
I have regenerated the model from the database and the relationships/column mappings all look good.
Any help, or any further information you need, would be appreciated.
Edit
I have built a LinqToSql alternative and it gives exactly the same error.

OK - I am a complete idiot!
I completely forgot that I added a trigger to the relevant table to update the pl_Items table but instead of using the correct table name I used Item_Id.
So the code from VS was all good it was the SQL Trigger in the back and that was screwing things up!

Related

Hibernate persisting incorrect values

I have some Hibernate code running against a Postgres 9.5 DB, which looks like roughly like below (anonymized) -
Integer myEntityId = myEntity.getId();
getCurrentSession().evict(myEntity);
myEntity.setId(null);
MyEntity clonedMyEntity = (MyEntity)getCurrentSession().merge(myEntity);
myEntity.setMyBooleanField(false);
getCurrentSession().save(myEntity);
I have an entity myEntity with a large number of fields. I want to create a duplicate of the record with only 1 field value changed. To achieve this, I evict the entity from session, set Primary Key to null, merge it back to session, set the field I want to change, and then save the entity to DB. However, this code (which was working correctly for some time), is not working now. It sees incorrect value for the boolean field I am trying to modify - as a result violating some database constraints. Please help me fix this or suggest a better way to achieve what I am trying.
The error was happening not on adding this record but on add of another record to an audit table, triggered by the addition of this record. A coworker suggested me to use Eclipse Breakpoint view and use the add breakpoint option there and select the ConstraintViolationException class - this helped me to see the error for which trigger was failing and why and accordingly modify the data to suit the database constraint.

Why do I get "unable to generate the model" errors when adding tables in EF?

Working in a team environment, someone just created some tables I needed to add (EF Database First design).
I chose to "Update model from database...", selected the new tables, and got an obscure error message:
Unable to generate the model because of the following exception: 'The value for column 'DataType' in table 'TableDetails' is DBNull.
Unable to cast object of type 'System.DBNull' to type 'System.String'.
'.
This is actually caused by trying to add a table with no primary key. Just update the tables to have a primary key and you shouldn't get this error anymore.
It would be nice if the error made this clear. It would also be nice if everyone remembered to set primary keys on tables when they created them.
Hopefully this will save others the fruitless efforts I had of searching for an answer.

MVC Entity Type Missing

I'm brand new to ASP.NET MVC (Literally just two days of learning on the fly). I'm trying to create a website using MVC, however, I've screwed something up in my solution.
I created this table that had foreign key constraints but I initially forgot to set up a primary key on the id field and forgot to set it identity specification to yes. So when I updated my DataModel and brought this table in, it showed every field as being the primary key and it showed the relationship to the other tables. So I went back to the database and changed the id field for the table to be the primary key and identity specification to yes.
I went back to the DataModel, tried to Update Model From Database, went to the refresh tab, expanded the tables, and selected the table I wanted to refresh, then click on "Finish".
The data model appeared to make the changes but it showed the relationships to the other tables twice.
So I thought I'd delete the table (entity) from the DataModel diagrahm and bring the table back in through Update Model From Database. But when I went back to the Update Model From Database...
Under the Add tab, the table isn't under the Tables
Under the Refresh tab, the table is listed, but when I select it and click on "Finish" the table doesn't reaapear in the diagrahm.
In the model browser...
Under Models
Entity Types, The entity isn't listed
Under Associations, The relationships no longer appear (obviously because the entity is gone).
Under Models.Store
Tables/Views, The table is listed.
Constraints, the relationships are shown.
I've tried dragging the table over to the diagrahm from the Model Browser, but that doesn't appear to work.
I've tried to right click in the diagrahm, add Entity but my table doesn't appear as a Base Type.
I've tried to google but I'm coming up with nothing. With this entity missing, I cannot even build my solution. Please help.
Try to delete the entity file and add it again. But you have to name it as previous entity and don't forget to delete the connectionString in web.config before add it.
If you don't know what I am saying just let me know.

EF4 is throwing an error "Schema specified is not valid"

I'm getting a weird EF4 "Entity Framework v4" error when I do a select on the context:
Schema specified is not valid. Errors:
The relationship 'AnalyzerConfigurationModel.FK_AnalyzerMetadataParameters_AnalyzerMetadata' was not loaded because the type 'AnalyzerConfigurationModel.AnalyzerMetadataParameter' is not available.
The query to generate the error is:
Using context As New AnalyzerConfigurationEntities
Dim EFAnalyzerConfiguration = (From P In context.AnalyzerConfigurations
Where P.Name = analyzerConfigurationName).FirstOrDefault
End Using
The schema is show below.
I've checked the connection strings, multiple times, its not that. Everything looks fine. I'm not sure if the XML that gets generated from this schema is off or not. But looked there too and don't see anything off or different from other properties. Has anyone run into this one before?
I found that if I expanded the EDMX file in solution explorer (VS 2012) and right clicked on each .tt file and selected Run Custom Tool also fixed the issue. This might be easier than de
Also make sure you're referencing project has the EntityFramework installed otherwise the dependent code will get this error.
https://www.nuget.org/packages/EntityFramework
Let me explain this:
The problem is because the system did not find consistency of the columns in database, the entities in the .edmx file and the model class and also the use of the same in the controller class.
So follow the following steps to fix this up:
Go to the database, check all the column names and properties.
Confirm them with the class diagram in the.edmx file. Right-click on the class in which you are getting the error, and select update option for the class. Select the Refresh tab in dialogue (if there is no new column added. if new column is added, you can select the add tab.) and select the relevant objects. Generally they are tables. So select them and finish.
Next check the names in the model class and the controller class.
This should be the solution. If not, let me know.
Are you using the SelfTracking Entity T4 template? I had this issue and found out the T4 template was not re-generating my entities after I had changed the Entity model in the Entity Designer. Try to right click the T4 Template and click "Run custom tool", and see if that helps.

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