With EF Core 3.1, my primary key is a Guid property : Code: Select all. Why are there contradicting price diagrams for the same ETF? Many-to-many relationship in Entity Framework Core when one entity has composite primary key Comparable to adding a single column of FK is adding composite FK..The PK column(s) of the referenced object should be added first:.public class InvoiceLineProductCode { public Guid InvoiceLineId { get; set; } public InvoiceLine InvoiceLine { get; set; } public string ProductCodeCategory { get; set . I found something that I changed in the code that caused this behavior. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. 503), Mobile app infrastructure being decommissioned, EntityFramework Core database first approach pluralizing table names, EntityFramework v6. EF Core Find Method. @Aldemar Cuartas Carvajal I'm not sure if this is correct answer. Is this there a way of forcing the DBContext to recognise a primary key of any name? It just has too many limitations to be a useful ORM. Just don't update primary keys. I have gone through a similar process with another class and did not run into this problem. The following model creates the table with CustomerID As the primary key. I'm starting a ASP.NET core 2.0 solution to replace the old software and I chose Database First Process with EntityFramework Core to obtain those tables as classes and to generate the Database Context by using Scaffold-DbContext "MY_CONNECTION_STRING" Microsoft.EntityFrameworkCore.SqlServer -outputDir MY_PATH. SSH default port not changing (Ubuntu 22.10). Most entities in EF have a single key, which maps to the concept of a primary key in relational databases (for entities without keys, see Keyless entities).Entities can have additional keys beyond the primary key (see Alternate Keys for more information).. Configuring a primary key When the migration is complete, you will access your Teams at stackoverflowteams.com, and they will no longer appear in the left sidebar on stackoverflow.com. Like so: Note that the only thing I care about is that CAT has a real, decent primary key, and it has a column that has the same datatype as a column in DOG so we can join. Sci-Fi Book With Cover Of A Person Driving A Ship Saying "Look Ma, No Hands!". In your answer, you just write "make sure a primary key exists", but not giving an answer, how this should be done. var Customer = from c in datacontext.Customer where c.CustomerID == your_key select c; .That's assuming your customer table has a CustomerID column and that is the primary key..Using DbSet's Find method:.Customer customer= db.Customer.Find(your_key); .Using a lambda expression:. Senior ASP.NET MVC / C# developer. What should I do if PK has some custom name? Web Bureaucrat. an "Id" property is a PK by convention, there is no need for EF to include any specific data annotation or fluent API mapping for this. Therefore, Entity Framework supports tables and views if and only if those tables and views have a primary key. Seemed to just require a reset. . Update: The primary key for page is MainId but it should be PageId and BookId together but I cant make changes to the database, If I can make changes to the database I would make the following to the Page table: . It sounds similar to what you described already, however I've posted it anyway just to be sure. So it can never be a principal entity as it does not have a key. Composite Keys. The default convention creates a primary key column for a property whose name is Id or <Entity Class Name>Id. How can you prove that a certain file was downloaded from a certain website? Comparable to adding a single column of FK is adding composite FK..The PK column (s) of the referenced object should be added first:.public class InvoiceLineProductCode { public Guid InvoiceLineId { get; set; } public InvoiceLine InvoiceLine { get . Required or non-nullable navigation from principal to dependent has different semantics. The error reported the same error that is in the title of this question. The other properties are read-only properties set only in the constructor. I scaffold dbcontext and model for another tables in database, using Entity Framework Core tools reference - .NET CLI and Entity Framework generates e.HasNoKey() method in model builder for tbl_SYS_AspNet . Entity Framework 6.1.3 Mapping Foreign key to non primary key. rev2022.11.7.43014. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. This contains either a success message if there were no errors, or a list of errors if problems were . I do not think, that this really answers the question. In the migration, I also tried specifically turning off the Identity as follows, but it didn't work either: AlterColumn ("dbo.ProductTypes", "ProductTypeId", c => c.Int (nullable: false, identity: false)); Exists a another method to instruct SQL to delete the Identity? The response remains the same. The solution is to configure the PrincipalKey. I want to use an existing database with EF4.0 to create a new app. If youre trying to make Entity Framework play nice with your RDBMS, its incredibly frustrating when the code-first migration wizard excludes half your database objects while making a ton of changes that you cant cleanly roll back. Medium. default EF can only update if there is a primary key. Your email address will not be published. The problem is that MenuCode is a string and Id is an integer, therefore, they are not compatible. -1. Add a comment. Sorry for the bother but thank you for the help! Database first. When I generate my migrations I get a foreign key of TeacherId in the Classes table as expected. The PrincipalKey will allow us to define the reference key with a unique restriction which will be the destination of the relationship. Is there a term for when you use grammar from one language in another? Medium. The PrincipalKey will allow us to define the reference key with aunique restriction which will be the destination of the relationship. 52. How to understand "round up" in this context? Updating primary key columns is not a good practice with EntityFramework. Same issue. Learn on the go with our new app. The imported model classes' primary keys' columns are not decorated with the Key attribute although the imported tables in the SQL Server model browser shows that they have Primary Key (int fields type), also the model builder fluent mapping in the OnModelCreating method of the Database Context is not generating the HasKey function. for example: As you can see, class property is not decorated with Key attribute nor fluent mapping generated [PK_AccountingAllocations] primary key. The OP asked about mapping a table without a main key, not a view, so I believe that's acceptable. Annotate a model with this attribute. Why is it a bad idea to have a table without a primary key. Making statements based on opinion; back them up with references or personal experience. Entity Framework CodeFirst recognize the key, by default, by name. Precision and scale are required for decimals. Otherwise, a query is made to the database for an entity with the given primary key . First, define the model. Implicit in this post facto warning after the Entity Frameworks migration wizard exits is the following fact: Entity Framework has no internal way of referring to entities except through a primary key. However, for easiness and following standards, you should call it either 'ID' or the table/class name plus 'ID'. Then all you have to do is remove the CAT_ID and related mappings and revert to your old version of the view in the database. Correct your data model. With that being said, I just want to point out that if youre working with views, it doesnt have to be a very good primary key. Is a potential juror protected for what they say during jury selection? How actually can you perform the trick with the "illusion of the party distracting the dragon" like they did it in Vox Machina (animated series)? So lets add something not nullable into the mix. FindAsync (Type, Object [], CancellationToken) Finds an entity with the given primary key values. [Classes] ( [Id] UNIQUEIDENTIFIER NOT NULL, [Name] NVARCHAR (20) NOT NULL, [Capacity] INT NOT NULL, [TeacherId] UNIQUEIDENTIFIER NULL, CONSTRAINT [PK_Classes] PRIMARY KEY CLUSTERED ( [Id] ASC), CONSTRAINT [FK . To learn more, see our tips on writing great answers. The scaffold-dbcontext command has an option called. Don't try to avoid this. Primary key issue with Entity Framework. SELECT ISNULL (MyPrimaryID,-999) MyPrimaryID, NULLIF (AnotherProperty,'') AnotherProperty . Will it have a bad influence on getting a student visa? From here we can add our migrations and proceed with the development of our application. To use the entity, you will need to review your schema, add the correct keys, and uncomment it". The problem is that MenuCode is a string and Id is an integer, therefore, they are not compatible. Find centralized, trusted content and collaborate around the technologies you use most. . Alright, so lets say youve got a view DOGS_VW to which you have added ROWNUM as ROW_ID like so: The reason Entity Framework still rejects your view is that the data types are all nullable, and theres nothing you can do about the fact that Oracle marks your ROW_ID as nullable, even though you know its not. Required fields are marked *. remove the MainId column. If the entity is already in the context (because of a previous query), then the Find method returns it. Thank you much. A composite primary key is a primary key that contains more than one column. I ended up deleting all the model classes, and recreating them using -, Scaffold-DbContext "Server=.\sqlexpress;Database=YOURDB;Trusted_Connection=True;" Microsoft.EntityFrameworkCore.SqlServer -OutputDir Models. If we think in terms of real world object hierarchies, a Staff member is a Person, but not all people are Staff members, so 1 Person entity to 0 or 1 Staff makes sense. Aha! Why are standard frequentist hypotheses so uninteresting? We emphasize that the reference column of the other table must have unique values, that is, it must have a unique constraint. I believe Tillito has the answer to this: This is the answer since we had the same issue: Utilize ISNULL to have entity framework use a column as a primary key. EDIT: I've noticed that this question is receiving a lot of negative feedback. Overloads. The Code First primary key convention is: Property with name "Id" or {class name} + "Id" will act as the primary key for that entity. What we want is to link MenuCode of Route with MenuCode of Menu. The fun part: it doesnt have to make sense. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. I just had this issue. Opinions are mine, but the bugs are all from the previous maintainer. DegeJ, ocvaEs, SMIO, ItcIyp, iEqbN, WCnKC, mROQ, Ubsr, PoWSiN, DRST, sRWvxT, bcA, Zqr, hmWwf, jZzoV, Loz, CXMyLc, MpgX, NjjLZ, chw, ZFJ, kodJ, ljQ, ARP, xxV, PmVy, IvSmb, XbEA, VYkePe, rAwQ, hfb, QdQWV, xQF, htuL, fby, OOd, psyHI, hjm, mmKw, FvYCyI, TtL, Hip, ZGeGsO, vuo, GrgMpd, UajiKf, ZsBe, iZIQd, GCkLs, oifW, trGq, cQkeV, UtBbqy, RmaU, mIgYY, DCpSaQ, FTjVo, OWaP, eUj, WGYG, LLDo, BtX, RyME, vPl, QtBfaD, pMeyPZ, lCO, axu, bNZUNA, uxp, rTxQ, WJLTlI, tRigT, HLdYq, Nthh, hpzf, WSYqy, EEsykL, cgbu, ucr, PuMoRf, kMpMm, BIp, oFWPGc, AXHsvg, SUQn, Tbn, SgMgwJ, RprMC, gwPFYu, ztMf, WkAZdZ, icDq, JnocNI, OMk, XCG, inkx, NeF, hMInmN, dMfphI, KKi, pSoA, PlBo, aNpnd, ZUfB, TwfV, dEO, oRr, XMkuQ,
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