using entity framework

Before writing the data Layer D layer when there are many SQL statements, how to omit the tedious SQL statements, Microsoft provides a good way-Entity Framework-entity framwork. An object mapping mechanism that supports. NET developers use domain-specific objects to come out of relational data, eliminating the need for most of the data access code that developers

] ([CategoryID]) On DELETE CASCADEAt the same time, from the script that generates the foreign key, it can be seen that the Entity Framework Code first generates a foreign key with the Cascade Delete feature enabled. That is, when a record in the Categories table is deleted, the database is automatically associated with deleting records belonging to that category in the Products table.The Products table gen

Active/passive state for the entity. Entities created for this reason, you can extend the Ipassivable interface to implement this functionality. The interface defines the properties of the IsActive. If the entity you created for the first time is marked as active, you can set the IsActive property value to True in the constructor. This is different from the soft deletion (isdeleted). If the

PortalContext.cs:View CodeNote: In the Onmodelcreating method of PortalContext.cs, the relationship configuration of the Fluent API form is added to the two entity classes category and product. For entity Framework Code First, the relationship between the two entity classes can be either added to the relationship mapp

SQL commands, many people in the information industry are studying how to integrate program design models with databases. The technology of object-relational ing is born from this, hibernate or nhib.pdf are the products of this technology, while Microsoft has ADO. net is a powerful tool for data access, but there is no tool for objects such as nhib.pdf. in the development period of Net Framework 2.0, an objectspace concept was proposed. objectspace a

" that lets you use the same conceptual application model through low-level ADO. NET data provider interfaces using Entity SQL, and audio stream results as possibly hierarchical/polymorphic datareaders, saving the overhead of materializing objects for read-only scenarios where there is no additional logic business. The Entity

provider uses the standard ADO and database to interact.The development model of the Entity frameworkThe Entity framework provides three development modes:1. Code First2. Database First3. Model First　　　　Code First:　　In the Code first development model, to avoid using the Visual Model Designer (EDMX), it is common to w

"> "Data source= (local); Database=portal; User Id=sa; password=; Multipleactiveresultsets=true"/> After you have set up defaultconnectionfactory for the Entity Framework above, using the Entity Framework to connect to the database does not need to be set elsewhere,

In the previous article, we created an MVC application using the entity Framework and SQL Server LocalDB, and used it to store and display data. In this article, you will modify the CRUD (create, read, update, delete) code that is automatically created by the MVC framework.Note: Typically, we create an abstraction layer between the controller and the data access

implemented using metadata. Entity Access: dbcontext can automatically construct SQL statements for related operations. Complex queries can be executed directly using SQL statements. After a dataset is returned, it is encapsulated or processed in the business logic layer. Actually, it cannot inherit the base class, implement your own personalized data access met

problems by using disable proxy creation.Here are some other ways to disable lazy loading: Omit the virtual keyword for a specific navigation property when declaring For all navigation properties, set lazyloadingenabled to False, placing the following code in the constructor of the context classThis. configuration.lazyloadingenabled = false; Create a courses page and display the department nameThe course

The full name of Entity Framework is ADO. NET Entity Framework, which is an ORM (Object/Relational Mapping) Framework developed by Microsoft Based on ADO. NET. The architecture diagram is as follows: When taking over a new project, we are familiar with and used to des

) Hibernate in the batch data processing is a disadvantage. (2) For an object (a single object) simple check change \ delete increase, not batch modification, deletion, suitable for using Hibernate, and for batch modification, deletion, not suitable for hibernate, which is also the weakness of the or framework; To use a specific optimization mechanism for a database, Not suitable for hibernate.

1. Installing the Entity FrameworkUse NuGet to install the Entity Framework Package: tools, library Package Manager, and Package Manager console, execute the following statement:Pm> Install-package EntityFramework2. Entity Framework Database Connection ConfigurationAfter the

Original article name: Entity Framework 4.1: Optimistic Concurrency (6) Address: http://vincentlauzon.wordpress.com/2011/04/17/entity-framework-4-1-optimistic-concurrency-6/We can see the English tutorial recommended for Entity Framework