Programming Entity Framework: Code First
Julia Lerman, Rowan Miller
Take good thing about the Code First facts modeling procedure in ADO.NET Entity Framework, and find out how to construct and configure a version in response to present sessions on your company area. With this concise e-book, you’ll paintings hands-on with examples to benefit how Code First can create an in-memory version and database via default, and the way you could exert extra keep watch over over the version via additional configuration.
Code First offers an alternative choice to the database first and version first techniques to the Entity facts version. research the advantages of defining your version with code, no matter if you’re operating with an current database or construction one from scratch. if you happen to paintings with visible Studio and comprehend database administration fundamentals, this booklet is for you.
- Learn precisely what Code First does—and does not—enable you to do
- Understand how estate attributes, relationships, and database mappings are inferred out of your sessions via Code First
- Use facts Annotations and the Fluent API to configure the Code First information model
- Perform complex recommendations, resembling controlling the database schema and overriding the default version caching
This ebook is a continuation of writer Julia Lerman’s Programming Entity Framework, well known because the major booklet at the topic.
to alter, although, is whatever in regards to the overseas key that also is concerned with this courting. Code First expects the international key estate to be named LodgingId or one of many different traditional names. So we have to inform it which estate really is the international key—AccommodationId. instance 4-9 indicates including the HasForeign Key way to the connection you laid out in instance 4-8. instance 4-9. Specifying a overseas key estate while it has an unconventional identify.
That even supposing we mapped basically the picture estate to the LocationPhotos desk, Code First labored out a shared fundamental key and a international key for that desk. It additionally created a PK/FK constraint among destinations and LocationPhotos. apparently, there isn't any cascade delete outlined for the LocationPhotos desk. yet Entity Framework is familiar with that for those who delete a vacation spot, it is going to need to construct a Delete command that spans either tables. Let’s look at the SQL generated through Entity Framework for.
dating. instance 5-31 indicates how one can upload the Map strategy to the connection configuration to specify overseas key names. 124 | bankruptcy 5: Using Conventions and Configurations for Database Mappings Example 5-31. Generated international key column configured HasRequired(l => l.Destination) .WithMany(d => d.Lodgings) .Map(c => c.MapKey("destination_id")); Now that you've got obvious this habit, cross forward and revert those alterations by means of uncommenting the DestinationId overseas key estate and elimination the.
Required relationships. 158 | bankruptcy 7: Advanced innovations While you may simply override the cascade habit for each required dating, when you've got loads of relationships, it can make extra feel simply to disable the conference altogether. Switching off conventions is finished within the OnModelCreating approach in your context through the DbModelBuilder.Conventions.Remove technique. upload the next line of code to OnModelCreating on your BreakAwayContext class:.
a piece weblog that either use a similar version. within the database you will have the tables used to shop the knowledge for this version replicated in separate schemas. The tables in your paintings web publication may possibly stay within the paintings schema (work.Posts, work.Comments, etc.) and the tables in your own web publication may perhaps stay within the own schema (per sonal.Posts, personal.Comments, etc.). each one of those units of tables is mostly a tenant. Database schemas are only a method to tell apart among tenants; there are numerous.