Lazy loading in linq c pdf

In this video we will discuss the concept of lazy loading in linq to sql with an example. How to efficiently use the lazy loading feature of entity framework. In an earlier column on lazy loading in entity framework ef, i implicitly. Efficiently loading related objects in entity framework visual. It is an entirely different concept by default and nhibernate doesnt have lazy loading, for exam.

Linq tutorials will help you to learn the linq language using topics which go from basic to advanced. When possible, it is best to lazy load the images on a page and only display them when the user gets to them, so it does not increase the initial page load time. Linq to sql, lazy loading and prefetching rick strahls. Languageintegrated query linq is a powerful query language introduced with. Lazy object loading is the default behavior for linq to entities.

This is the typical way in which iterators are implemented. Lazy loading means the related entities are not loaded, until we iterate through them or bind them the data. Lazy loading in an orm can be really useful or a royal pain if you walk through a lot of data. Best practices for lazy loading in entity framework visual studio. The dbcontext class enables lazy loading by default. Best practices for lazy loading in entity framework. Eager loading helps you to load all your needed entities at once.

Learn about lazy loading queries in entity framework 6. Leseprobe effizienter datenzugriff mit entity framework core. Lazy loading is the default behavior for an object context that has been generated by the designer. There is onetomany relationship between department and employees entities. Linq to sql, lazy loading and prefetching rick strahls web log. Entity framework defaults to lazy loading and allows you to override it. Maximizing performance with the entity framework 4. When the entity is read, related data is retrieved. By default, linq to sql loads the related entities, using lazy loading. Dependency injection using microsoft unity application block di ioc 30 minutes training duration. Eager loading, lazy loading and explicit loading in entity. In eager evaluation, the first call to the iterator will result in the entire collection being processed. The related data is transparently loaded from the database when the navigation property is accessed. Enable or disable lazyloading in entity framework ryadel.

In the lazy loading, the context first loads the student entity data from the database, then it will load the studentaddress entity when we access the studentaddress. If you want the child objects for every parent object then you dont want lazy loading you want to retrieve child objects when you retrieve the parent object. Lazy loading means delaying the loading of related data, until you specifically request for it. How do you construct a linq to entities query to load child objects directly, instead of calling a reference property or load there is no other way except implementing lazy loading. Lazy loading is the process whereby an entity or collection of entities is automatically loaded from the database the first time that a property referring to the entityentities is accessed. Linq to sql uses lazy loading of related entities and entity sets but there are a couple of ways that allow you to do eager loading instead. Lazyloading in entity framework entity framework tutorial. For example, the student entity contains the studentaddress entity. Lazy loading is delaying the loading of related data, until you specifically request for it. Eager loading causes entity framework to retrieve the parents and child objects with one. Eager loading in entity framework entity framework tutorial. Just use the include method in your linq query to turn on eager loading.

If you have a linq query that you expect to run repeatedly in the life of an object. Lazy loading means delaying the loading of related data until you specifically request for it. It is enabled by default in entity framework, and you dont need to do anything. Nhibernate lazy loading in this chapter, we will be covering the lazy loading feature. The dbcollectionentry objects query method returns the linq query thats used to retrieve the items in the collection. Linq to sql uses lazy loading of related entities and entity sets but there are a. This tutorial series builds on the contoso university web application that is created. Net and java apis for file formats natively work with docx, xlsx, ppt, pdf, images and more.