entity framework example

Small instance of the entity Framework: Adding an entity class to the project and inserting1>. Create a console program2>. Add an ADO. NET Entity Data model, select the corresponding database and table (STUDENTMODEL.EDMX)3>. Control Table Code Static voidMain (string[] args) { //Create a gateway inter

When you generate an ADO. NET Entity Data Model (Entity Data Model) through a database, the number of entity classes generated may be less than the number of data tables. The following describes two possible causes. 1. All columns of the data table can be empty. When a data table has a primary key, the object data model uses the primary key as the

hierarchy scenario. In this way, we can still use the Expression /// However, this Expression For this reason, how should we pass the Expression /// We need to construct an ExpressionNode object for processing in the client interface. The Query Processing code is as follows. Here, we need to first process Expression Private ExpressionNode GetCondtionSql () {Expression On the implementation side of the Facade interface, we need to turn the ExpressionNode into an Expression /// In this

From the blog Park development team to develop frontline news:In the Entity Framework, if entity A is associated with entity B, you want to load entity B while loading entity a. It is common practice to use include () in LINQ quer

Entity Framework 6 Recipes 2nd Edition (9-5) Translation-> delete a disconnected Entity, entityrecipes 9-5. delete a disconnected entity Problem We need to delete the object retrieved from WCF. Solution Let's assume that we have the payment and Bill model of the entity as sh

Entity SQL is the SQL class language provided by the Ado.net Entity Framework to support the Entity Data Model (EDM). Entity SQL can be used for object queries and queries executed using the EntityClient provider. L Key Words Value keyword ESQL provides a SELECT value cla

If lazy loading enable = true is not set in the Entity Framework, the handler must handle the loading of the metadata, for example, using load or include, however, because the include parameter number is string, it is very difficult for a person to find the parameter easily after tablename is changed with string, so I want to introduce an extension method. // Adv

Familiarity with the Entity Framework should be not unfamiliar to the film, he is the ADO Entity Data Model Wizard: You can automatically generate a model class for a database table, or create a model file for code first.However, this Model wizard only displays Microsoft's own SQL Server data source by default, and if you want to use a MySQL data source, you have

the model. These returned objects are a very important part of query processing. Of course, you want to start the query. First, let's query the objects and then peek at the background. Your first EDM Query In Chapter 2nd, you create an EDM instance in a console program. Now you create your first query for this EDM. You can use the same project, so if you close it, open it and we are about to begin. In this sectionCodeThe simplest Query Form is executed. It returns each contact

Http://www.cnblogs.com/dudu/archive/2012/04/13/entity_framework_include_where.htmlIn the Entity Framework, if entity A is associated with entity B, you want to load entity B while loading entity a. It is common practice to use inc

Today, I just learned the razor of MVC and used the Entity Framework together. The following error is returned: Cs0012: the type'System. Data. Objects. dataclasses. entityobject' IsDefinedInAn assembly thatIsNot referenced. You must add a reference to assembly'System. Data. entity, version = 4.0.0.0, culture = neutral, publickeytoken = b77a5c561934e089'.

already appears in the database list:And you can find our pre-prepared data:The database structure generated automatically by the Entity Framework is as follows:Of course, we don't need to focus too much on this data model at the moment, after all, we're not going to database-oriented programming.Start using the Entity Frame