Updating data using linq

23-Oct-2019 05:17

whether the DAL uses EF, another ORM or manually creating connections and commands to execute queries against a data source. For EF to enable features such as lazy loading and automatic change tracking for POCO entities, it can create a wrapper class around the POCO entity at runtime.

Besides the abstraction it brings it’s also great if you are using dependency injection in your application. There is a certain set of rules that your entity classes need to follow to get this proxy behavior.

In this case you could expose an Add method and an Update method for each entity type and these methods would only operate on a standalone instance rather than a graph of entities. It is all about setting the state of the passed in entity object.

An entity can be in one of five states as defined by the : the entity is not being tracked by the context at all.

updating data using linq-10

You then use the Save Changes method on the context to persist the changes back to the database.For example, when you want to insert a new object is the root entity.On the server side, things will get easier if you decide to not support graphs.Add a new class library project () to the solution in Visual Studio. Open File Explorer (right-click on the solution in Visual Studio and choose the “Open Folder in File Explorer” option) and move the file to the new project folder. Back in Visual Studio, include the file in the new project by clicking on the “Show All Files” icon at the top of the Solution Explorer and then right-click on the file and choose the “Include In Project” option. Note that if you make any changes to the model in the DAL project later on you are required to explicitly update your model classes.By right-click on the template file and choose “Run Custom Tool” the entity classes will be regenerated to reflect the latest changes to the model. As the context by default expects the entity classes to be in the same namespace, add a using statement for their new namespace to the Model. Finally, you need to add a reference from the DAL project to the domain model project in order for it to compile.

You then use the Save Changes method on the context to persist the changes back to the database.For example, when you want to insert a new object is the root entity.On the server side, things will get easier if you decide to not support graphs.Add a new class library project () to the solution in Visual Studio. Open File Explorer (right-click on the solution in Visual Studio and choose the “Open Folder in File Explorer” option) and move the file to the new project folder. Back in Visual Studio, include the file in the new project by clicking on the “Show All Files” icon at the top of the Solution Explorer and then right-click on the file and choose the “Include In Project” option. Note that if you make any changes to the model in the DAL project later on you are required to explicitly update your model classes.By right-click on the template file and choose “Run Custom Tool” the entity classes will be regenerated to reflect the latest changes to the model. As the context by default expects the entity classes to be in the same namespace, add a using statement for their new namespace to the Model. Finally, you need to add a reference from the DAL project to the domain model project in order for it to compile.Entity Framework (EF) is Microsoft’s recommended data access technology when building new . It is an object-relational mapping framework (ORM) that enables developers to work with relational data using domain-specific objects without having to write code to access data from a database.