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Showing posts with the label Entity Framework

CRUD operations using ASP.NET Core 2.0 and In-memory database with Entity Framework

In this article, we will create a Web API with in-memory database using Entity Framework and ASP.NET Core 2.0 without any theoretical explanation. To know more on concepts and theory, my previous articles can be referred. Let’s quickly create a new ASP.NET Core application by choosing API template and name it as ConferencePlanner. Add a new Model entity named Workshop inside a newly add Models folder as shown below: public class Workshop {     public int Id { get ; set ; }     public string Name { get ; set ; }     public string Speaker { get ; set ; } } Here we are going to use in-memory class along with EF. So, we have to add a new class for setting up the database context as shown below: public class ApplicationDbContext :DbContext {     public ApplicationDbContext(DbContextOptions<ApplicationDbContext> context): base (context)     {     } } Now we have to maintain multiple workshops under a conference. So, g

Verify database prior to data insertion via EF

Recently, one of my colleague got a requirement on inserting data into database using EF. His issue was, how to verify if the database schema is proper or say all the columns in the tables matches with his POCO entities. Hope few of you must have come across similar scenarios. Here is the quick solution for this. In such scenarios, developers can do the schema compatibility check prior to inserting any data into the columns to ensure that model class still holds good with database tables. bool isModelValid = yourContext. Database . CompatibleWithModel ( true ); In the above method, passing the correct boolean value will do the trick for us. If the parameter value passed is true, then the framework will throw an exception if the schema doesn’t matched with your model class. Isn’t it a useful tip? Happy troubleshooting!!!

EF warning while using Database first approach

Error 6002: The table/view 'AdventureWorks.dbo.BuildVersion' does not have a primary key defined. The key has been inferred and the definition was created as a read-only table/view. Explanation: The above warning is generated when you use Database first approach for Entity Framework model creation. Such warning appears due to entity key. Every Entity needs to have an entity key and when EF creates an entities, what it does is, it tries to find an primary key from the database and creates an entity key from that.  But it may be the case that few of the database objects doesn't have primary key defined. In that case, EF tries to infer a key based on your view or table's columns. So, here it becomes necessary to have at lease a non-null column in your database object.  It's just a warning, so nothing harmful here. But still if you need a solution to get rid of this warning, then it is posted by Hilmi Aric.