Ef core recursive include. NET Expression, or generate one in SQL.

Ef core recursive include I need to load child pages recursively. Entity<Article>(). I'm on . It would also be great if there was an "AlsoInclude" so that when you want to include another peer several levels deep, you don't have to start at the top (with Include) again. Courses . Children): In this line, p is an object of the main entity type you're querying, let's say Parent. Chapter") . IsDecendantOf to get a specific item and all ancestors. Aug 25, 2020 · One of the very common questions I am getting from . Então, mesmo se você não incluir de forma explícita os dados para a propriedade de navegação, a propriedade ainda pode ser populada se algumas ou todas as entidades Sep 12, 2023 · Even though there is no database structure to represent an IGrouping, in some cases, EF Core 7. 3. Eager loading is the most straightforward way to avoid N+1 queries in Entity Framework Core. Mar 19, 2019 · The extension method Includeis a mere wrapper around DbQuery. Is EF Core support this Feb 4, 2017 · Entity Framework recursively include collection for each entity from included collection 0 Issue with recursive tree traversal in c# Jan 16, 2024 · I have an old database that I'm converting from using pure SQL queries to using Entity Framework Core instead. Include(p => p. The second case will be done with one query to the database. Ask Question public static IQueryable Include(this IQueryable source, IEnumerable Feb 18, 2024 · Reasoning: This feature would enhance the flexibility of working with IQueryable instances in Entity Framework Core. The API for eager loading is very different in EF Core and the simple Func<T,object> delegates or strings don't work anymore. com/course/net-core-31-web-api-entity-framework-core-jumpstart/?referralCode=CA390CA392FF8B003518🔥 Blazor Bootca Jul 9, 2019 · What the issue is Querying a many-to-many relationship retrieval returns infinitely recursive object graph. I am creating a greenfield application that uses EF Core which must talk to a legacy database. I have 2 classes: public class PermissionGroupDefinitionEntity : IEntity { public I'm new to . Referrer. There are three common O/RM patterns used to load related data. The structure in which the solution that I will present you work is a structure that look like a tree. Pages can have other pages as well as items. Is it possible to retrieve only the desired data with a single select? We are using Entity Framework 6. 2. So even if you don't explicitly include the data for a navigation property, the property may still be populated if some or all of the related entities were previously loaded. NotSupportedException' occurred in EntityFramework. May 1, 2021 · Some remarks for the comments above, although contextually they're probably meaning EF Core - In EF6 a circular Include() will cause exception when using AsNoTracking(). 1 to 6. Referred). BlogPosts . 1 Database provider: (e. Ask Question I know I can use Include and ThenInclude, but my categories subs is infinite. So, It can be done by creating a stored procedure in SQL Server and calling it by using a functional import. The option FlatListRecursionLevel let you include boss in Jul 8, 2016 · Is there a way to decorate your POCO classes to automatically eager-load child entities without having to use Include() every time you load them?. e. This story is one of Aug 14, 2023 · A HierarchyId is a common solution to issues like this. Let say we have the following model: public class Hierarchy { public int Id { get; set; } public string Name { get; set; } public Hierarchy Parent { get; set; } public ICollection<Hierarchy> Children { get; set; } } Apr 28, 2020 · Eager Loading in EF Core. However, this is going to create Apr 23, 2019 · Eager loading using "include" generates one big query to fetch all the related Entities and EF has no way to express a recursive query using a . Jun 22, 2015 · When I do a LINQ to Entities query for a specific Item, it doesn't return the related Category, unless I use the Include("Category") method. Apr 2, 2013 · The Include is a Eager Loading function, that tells Entity Framework that you want it to include data from other tables. 0, EF Core 1. . The other two ways of loading data are Lazy Loading & Explicit Loading. This story is one of the possible ways to do it. All entities are loaded in a single query to database thus saving bandwidth and crucial server CPU time. 1 Operating system: Windows 10 & OSX IDE: Visual studio 2019 & IntelliJ Rider Jan 4, 2019 · or AutoInclude fluent API (EF Core 5. var blogArticles = context. Sep 13, 2023 · O Entity Framework Core corrigirá automaticamente as propriedades de navegação para outras entidades que forem carregadas anteriormente na instância do contexto. Eager loading is a technique where EF core loads the related entities along with the main entity. NET software framework. May 10, 2024 · I'm using EF Core 8. I have an "account" table that includes a string foreign-key ("parent_guid") to its "parent" account (if one exists). People) Entity framework query to include child entities of entity collection. From this: Entity Framework include collection/reference where. Include(c=>c. You can drill down thru relationships to include multiple levels of related data using the ThenInclude method. It is available in EF 4. 3. NET Core Web API and Entity Framework Core. I want EF to ignore some of the columns in the database because they will eventually be deprecated and I don't want them in the new entity model. NET community is how to configure and use the tree structures in EF Core. g. Jul 11, 2021 · I'm using EF Core for my project. NestedProp) If so what is the point in using Include / ThenInclude as they both work and produce the same SQL. Modified 6 years, 6 months ago. We will re-assess the backlog following the this release and consider this item at that time. It's a powerful tool for loading related data, and mastering it can significantly enhance your application's performance and efficiency. EF Core version: 3. Sep 10, 2019 · In accordance with my model, I want to extract the data as a tree list at once. Internally it does not execute the expressions but only parses them, i. Author) . Here's my (simplified) table structure: ProductCategory Id CategoryChidrenKey Name CategoryChildren Id Key ChildCategoryId Nov 17, 2020 · I am working with EF Core 5, trying to get a many-to-many relationship working with the newest methodology, following the documentation here and here, but every time I try to implement load the related entity, it enters a recursion loop and throws and exception because it detects an object cycle. Includes for some navigation properties. My issue is that I want to recursively get ALL child nodes of a particular node in the hierarchy. Entity Framework Core, a powerful Object-Relational Mapping (ORM) tool, provides us with Include and ThenInclude methods to optimize the retrieval of related data. 4 Database provider: Microsoft. Microsoft Technologies based on the . Querying related entities Apr 28, 2022 · Include provider and version information. This post explains why this approach is flawed and its usage may actually be a sign of an underlying problem - a problem that is made even worse by the use of Include. Trying to do so leads to runtime exception. Either recurse through the results and using Explicit Loading or Lazy Loading fetch the levels of children, or load all the Entities and let the Change Tracker Jan 29, 2019 · Entity Framework Core Recursively Include Problem. EF7 . So I wrote a Get -method that does it for me: First, this is my RecursiveEntity<T> base-class: [Key] public int Id { get; set; } where TEntity : RecursiveEntity<TEntity> public virtual TEntity Parent { get; set; } Apr 8, 2021 · In this short post, we’ll explore how to model a self-referencing entity with EF Core and then create a helper method that will allow us to get all downstream data starting at a particular level. it takes their member expressions and converts them to a path as string. Feb 19, 2019 · So how could the same soltuion be applied to EF Core? Eager loading with simple delegates for EF Core. Include. SqlServer) Target framework: 3. Eager loading means that the related data is loaded from the database as part of the initial query. Like this: db. The Children property is a navigation property in Parent. And I have a problem with nested query in EF Core. The following LINQ query uses the GroupBy operator to group the results by the Mar 21, 2025 · If you're a developer working with Entity Framework Core (EF Core), you've probably come across the Include method. Abstractions package doesn't reference any other packages, and so has minimal impact on deployed application size and dependencies. I can't remove them yet as the legacy system still relies on them. My Web API starting choking when I added . 0 和更新版本可以在从数据库返回结果后创建分组。 这类似于 Include 运算符在包含相关集合时的工作方式。 以下 LINQ 查询使用 GroupBy 运算符按 Price 属性的值对结果进行分组。 Jan 22, 2020 · EF Core Include on multiple sub-level collections (1 answer) Closed 5 years ago . Include("Lab") . To follow along, developers will need a running instance of Microsoft SQL Server. @mc Hi, have you got any updates? This sample demonstrates how you could implement recursive or hierarchical queries using EF Code First for a self-referencing table or entity. NetCore5中利用Entity Framework（EF）进行无限级树形结构的查询。通过示例代码展示了如何查询所有根节点的部门，并强调在查询时不应使用AsNoTracking以确保能加载子级内容。查询结果经过排序和过滤，返回不包含父节点的部门列表。 Jan 6, 2020 · // context being DbContext var res = context. Using Lambda Expression May 4, 2023 · In this article, Michael Ceber explains how to write a recursive projection query in C# and Entity Framework Core to efficiently load hierarchical tree structures from a database. NET Core 1. Aug 24, 2023 · HierarchyId is designed to work with EF Core, but it can also be used outside of EF Core in other applications. Apr 22, 2020 · EDIT: This is the answer Is recursive query possible in LINQ It was already answered there must have missed that one. StorageStuff) . Sep 11, 2017 · EF (and LINQ in general) has issues loading tree like data due to lack of recursive expression/CTE support. 0, IterationCount 100) When you're using Entity Framework Core's . From the question, I assume your project structure is as follows: One thing that is crucial to notice is that the circular dependency is between TenantSecurityService and the persistence layer, not between ITenantSecurityService and the persistence layer (since an interface doesn't have an implementation that depends on the data layer). Nov 12, 2015 · For . I'm not an expert but try putting Virtual in front of both of them like in all examples. Then they try to set up EF to work with it and go "EF can't do what I want!" Vast majority of the time, reducing complexity makes EF very comfortable to use while solving the same problem more efficiently. Subject); As properties are lazy-loaded, I expected each subject to only contain their "Name" property. 预先加载是指对一种实体类型的查询同时加载相关实体作为查询一部分的过程。 预先加载通过 Include 方法实现。 例如，以下查询将加载博客以及与每篇博客相关的所有帖子。 Jan 4, 2022 · 🚀 . For example, . Feb 10, 2019 · In EF Core 3. In the repository/UoW or business layer you could use the same technique to "assemble" the finished entity by having a property of a method that calls the method recursively. Invoices) . Single(x => x. However, keep in mind that there are many other high priority features with which it will be competing for resources. I would like to create an entity that knows its parent, as well as all of its children. udemy. NET Web API, EF, EF Core, ADO. Referrer) This will pull patent and grandparent. ApplicationsWithOverrideGroup. When asking for query assistance on the forum, you should provide make an effort to provide sample data the community can use to populate a table. Referred) This will pull affiliates along with their children and grandchildren. 0). An unhandled exception of type 'System. So, the solution was to add dbContext. works with Entity -> Property, but doesnt work with Entity -> Property -> Property of previous property, in which case you need to invoke the fully qualified string syntax - <PropertyName>. Affiliates. 1 – Indigo_heart. For example, I have The problem in the code: a) You expect that every property is navigatable b) It has to be recursive to go deeper than one level, e. 0+) modelBuilder. NET, LINQ, SQL Server, MYSQL, Oracle, ASP. The Eager Loading is in EF Core done using Jul 13, 2018 · I guess behind-the-scenes, it's doing the recursive work for me. But it can be achieved. Children). Use Include collection in Entity Framework Core. Currently, developers commonly create virtual methods, use the Include method for each navigation property, or resort to reflection and expressions for similar scenarios. For one-to-one navigations you can use: context. Entity Framework core . Aug 19, 2020 · How does Entity Framework work with recursive hierarchies? Include() seems not to work with it. Navigation(e => e. Viewed 24k times 32 . Collection(n => n. Include() and . NET community is how to configure and use the tree structures in EF Core . I really don't know how to tell EF to map all child Projection the same way than their parents. NET Core, Cloud Computing, Microservices, Design Patterns and still learning new technologies. x async queries. NET Jumpstart Course: https://www. <NestedPropertyName> Aug 24, 2023 · 本主题所介绍的方法同样适用于查询使用 Code First 和 EF 设计器创建的模型。 预先加载. So, even when the tree was being populated, the proxies were triggering an extra load when Children was accessed. 2. But due to EF Core implementation specifics, owned entity types cannot use explicit/lazy loading. Feb 17, 2021 · I have an SQL-Table which is build like a tree list (parent child). Include() issue. This story is one of the possible way to do it. Include("Childs. If you need to walk the entire tree, you should use a stored procedure. Another thing is using Linq in Entity Framework. ie get the root asset from the context and it's children will be there. NET Core 2. Proxies nuget package and then call . To use lazy loading you need to add Microsoft. Oct 24, 2023 · Entity Framework Core has the Include operator that can be used to load related data. Microsoft. net core the syntax is now . Permission . Pranaya Rout has very good experience with Microsoft Technologies, Including C#, VB, ASP. Ask Question Asked 8 years, 11 months ago. I've looked through multiple questions asked on this site and none of the answers worked for me. – Sep 23, 2017 · This has been asked several times since it was de facto a standard of specifying the desired includes to repository methods using EF6. Each entity has a ParentId. Like the Include method, by default, the entity from the hierarchy is materialized but not part of the returned list. All you need is a single Include and then the EF Aug 25, 2023 · This issues a join to load all customers and orders in one query. I get the child nodes quite easily using Linq: Sep 15, 2021 · 本文介绍了如何在. Staffs . Jan 17, 2024 · Entity Framework Core: DbContextOptionsBuilder does not contain a definition for 'usesqlserver' and no extension method 'usesqlserver' Related questions 834 Feb 26, 2023 · Entity Framework - Include Multiple Levels of Properties; Entity framework linq query Include() multiple children entities; Answer Entity Framework 4. If the ParentId is null then that element is a root item. NET 6. Jan 4, 2018 · In order to get the Product, we just need to use the “ThenInclude” method to include a property from a sub-item. I currently have 3 tables, two normal tables and one linking table. Feb 19, 2024 · @ajcvickers Thank you for directing me to the Entity Framework Core change tracking article. An easy and clean way to fix this is to use implicit includes over explicit ones. Grades). Jun 16, 2020 · 文章浏览阅读704次。本文探讨了如何在Entity Framework中使用Include方法加载对象的多级属性。当需要深入到第二个甚至第三个级别时，文章提供了针对EF 6和EF Core的不同解决方案，包括使用ThenInclude方法和第三方库。 Sep 11, 2023 · Совет. My class looks like this: public class Patch : EntityBase { [Key] pub Mar 7, 2020 · of course you have recursion. Jun 5, 2019 · In Entity Framework Core we can have recursive entities. ToList(); Dec 11, 2018 · This issue is in the Backlog milestone. Include(x => x. The Microsoft. ThenInclude(cc => cc. Add a comment | -3 . Include supports recursive loading to arbitrarily nested depths. However, upon inspection, I found that the "Grades" list is also set, with a list of all the grades assigned to the subject. But it doesn't bring the full category, with its parent and children. Feb 23, 2023 · EF Core has a new extension method ThenInclude(). With EF Core 8 you can use . In this case, the Product (property in OrderItem Aug 13, 2012 · As illustrated these recursive queries are slow. Some stackoverflow post mentioned that it doesn't occur in EF Core. EF Core version: 6. Today, we're going to explore the ins and outs Feb 3, 2020 · I am using . But in case you want to load the whole tree (as opposed to filtered tree branch), there is a simple Include based solution. My EF entity has a Parent navigation property, my DTO to map to looks a little like this: public class CompanyInChainDTO { public Guid Id { get; set; } public string Name { get; set; } public CompanyInChainDTO Parent { get; set; } } Aug 9, 2022 · I have a data structure, such as next class Entity { int Id, int EntityParentId, string Name } And I would like to get all children or parents, could you help me how can I do it with C# LINQ Jan 19, 2023 · Entity Framework Core will automatically fix-up navigation properties to any other entities that were previously loaded into the context instance. Apr 29, 2020 · Entity Framework - High Performance Querying Using Temp Tables April 24, 2020 Today I came across a nice article explaining how we can optimize a query with multiple Include() of related entities. ThenInclude(), they're intended to work on different levels of your object hierarchy. Here Jan 4, 2018 · The following code was taken from Luke McGregor’s repository called LinqExpander and updated to support . Include(a => a. You can then query an entity for all its descendents or all its ancestors. 1 with Lazy load proxies. NET Expression, or generate one in SQL. 0) with Linq and GroupBy clause I noted that the ThenInclude method does not properly receive the objects Steps to reproduce // NOT WORKING EXAMPLE var query = context. NET Standard 2 and Entity Framework Core 2. I like the Include(). ToList(); } Oct 21, 2016 · The ThenInclude pattern allows you to specify a path from the root to a single leaf, hence in order to specify a path to another leaf, you need to restart the process from the root by using the Include method and repeat that for each leaf. Here's a Feb 15, 2010 · I'm using Entity Framework Core 3. Apr 12, 2017 · Entity Framework Core will automatically fix-up navigation properties to any other entities that were previously loaded into the context instance. Childs"), would load three levels. Aug 26, 2020 · One of the very common questions I am getting from . NET MVC, ASP. 0, VS 2015. If you want to use the traditional signature, you have to first decompose the delegate into parts. It was inspired by his blog post Composable Repositories - Nesting Extensions where he talks about single element projection. UnitesChild in my query and it will do the magic and set cascaded relations between Unites. 0. UseLazyLoadingProxies() when you configure the context. This means that it is not planned for the next release (EF Core 6. Dec 18, 2019 · Include all navigation properties with recursive properties EF Core. Jan 24, 2017 · In fact loading the whole hierarchy is quite easy thanks to the so called EF (Core) relationship fixup. Right now, I'm working on threaded comments à la Reddit and I'm using adjacency list + recursive CTE to retrieve a comment and its replies (children). 1. NET Core and I'm working on a CRUD app to learn more. Jan 7, 2014 · I am using Entity Framework (version 6) to map to a recursive hierarchy and it maps nicely. Mar 1, 2023 · Include boss, but only direct one; Include boss, but with custom mapping; Include boss, but with an inverse navigation; Include boss, and add them in the returned list. SqlServer Target framework: . Sep 27, 2015 · context. It would be interesting the hear some EFC team member what was the reason behind the decision to change the pattern to Include / ThenInclude which apparently cannot be represented this way, and more importantly, what's the EFC replacement. I'm writing a system for posts/comments, and I need a function to load a comment and all of its children and their associated properties. SqlServer. I am trying to get the accessory by itse Mar 15, 2023 · EF Core使用Include和join 在EF中表连接常用的有Join()和Include(),两者都可以实现两张表的连接，但又有所不同。 例如有个唱片表Album（AlbumId,Name,CreateDate,GenreId），表中含外键GenreId连接流派表Genre(GenreId,Name)。 Hello, if for EF core this does indeed work . May 26, 2023 · Recursive load for load data with EF Core. Nov 27, 2019 · Circular project references. EntityFrameworkCore. About the Author: Pranaya Rout Pranaya Rout has published more than 3,000 articles in his 11-year career. 尽管没有表示 IGrouping 的数据库结构，但在某些情况下，EF Core 7. He discusses the limitations of traditional queries and presents a recursive method that applies a projection of Category to CategoryDTO and queries all subcategories Mar 11, 2021 · Entity Framework Core allows you to use the navigation properties in your model to load related entities. Jul 25, 2022 · If change tracking is enabled, then when a query materializes an entity, EF Core will automatically set the navigation properties of the newly-loaded entity to refer to any entities already loaded, and set the navigation properties of the already-loaded entities to refer to the newly loaded entity. The common tree People bad at database architecture build the databases that make navigation through objects needlessly complicated and inefficient. Most of the work is already done, but I'm having problems with a recursive tree structure. EF Core 5: Include With Where Statement Followed by ThenInclude -- Inheritance Problem. using ( var context = new MyContext()) { var customers = context. EF Core автоматически исправляет свойства навигации для других сущностей, которые были ранее загружены в экземпляр контекста. The Include() method allows the required depth of eager loading to be specified by providing Select expressions to the appropriate depth. SQL Server and EF Core 8 have full support for this type, though you can use it with earlier versions AFAIK, just not query against it as nicely. Include(i => i. By proactively including related data, it prevents the context from needing to issue separate queries later. Customers . Means you have rootId's and childId's. 1. Developers often use AsNoTracking in the belief that it will increase performance when performing read queries in Entity Framework. Include(s => s. NET Core 3 with the latest Entity Framework Core. Cities). IsLoaded = true; for each of the returned nodes. Still, I guess it's notable that circular references might be issue in older versions of EF. ThenInclude(it => it. Edit: This is what I have tried so far. All the solutions I found either hardcoded the depth of the hierarchy (using Include ) or do the recursion in C#. AsNoTracking() . 0 and newer can create the groupings after the results are returned from the database. Entity Framework is particularly ill-suited for recursive relationships. InvalidOperationException: CurrentDepth Mar 1, 2017 · I'm having some issues which I'm guessing are related to self-referencing using . public class FolderInResearch : EntityBase { public FolderInResearch() { SubFolders = new List&lt; Jul 18, 2018 · Clarification: The use of _context in the recursion is not allowed by EF and was used for illustration purposes. ThenInclude(g => g. Dec 6, 2016 · I'm on . Are you trying to create a recursive query? If so, the entity is not designed correctly. . In SQL Server it is used in this format; SQL: Feb 13, 2017 · Use just the Include extension on IQueryable. Oct 24, 2023 · In this case, developers can think that Entity Framework will analyze the usage of the data they manipulate to optimize the query but it does not so if you ask Entity Framework Core to return some data you don't need, it will do it. 1 assembly. The CTE I have is: Aug 27, 2020 · EF Core will automagically load in the related entities for you as you access them. Student. May 4, 2023 · In this article, Michael Ceber explains how to write a recursive projection query in C# and Entity Framework Core to efficiently load hierarchical tree structures from a database. I have this var page = await dbContext Aug 22, 2013 · Posted on: 2013-08-22 Everything has many way to do it, here is two ways to handle data structure that is recursive. I've carefully reviewed the information, and while it provides valuable insights into entity states and how DbContext instances track changes, it seems that the described behavior doesn't fully address the specific scenario I'm encountering. Include Issue. It contains pages. I am trying to query an entity with multiple levels of collections, and multiple collections at a single level. You'll either need to issue N+1 queries for each level, or eagerly load a defined set of levels. The Include syntax can also be in string. Placeuser is inside place and place is in placeuser. Jan 16, 2017 · When using Entity Framework Core (v1. Feb 17, 2021 · My purpose for recursive SQL CTE is to do search of hierarchically structured data in table (id-parentId). Commented Feb 2, 2023 at 20:40. Oct 5, 2023 · As an experienced web developer, I know that efficient data retrieval is crucial for building high-performance applications. This is similar to how the Include operator works when including related collections. Aug 24, 2023 · このようなフィルターは、EF Core によって、これらのエンティティ型に関係する LINQ クエリに自動的に適用されます。 また、EF Core によって、Include またはナビゲーション プロパティを使用して間接的に参照されるエンティティ型にも適用されます。 Apr 29, 2020 · The following example demonstrates an hierarchical query using C# and EF Core using ELINQ: int ? managerId = null ; //external parameter - "highest" manager id DbContext . I can use a recursive function into my select; So this is the final code : Sep 7, 2020 · Include() seems not to work with it , How to do recursive load with Entity framework? and a bunch of others which they are all old. The exception is not actually thrown, however it can be seen in the output window System. ThenInclude(a => a. Entry(treeNode). They are structured below. dll. and doing this using Entity Framework is even slower. If you don't want to reference that assembly in your upper layers create wrapper extension method in your data access assembly. ThenInclude() syntax of EF Core. But we cannot do an "Include" for these recursives (can we?). I have a catalog system. 0 Operating system: Widnows Server IDE: Visual Studio 2022 Feb 14, 2022 · I'm trying to setup an entity framework class which has 4 fields that link back to others of the same type or are null. Childs. AutoInclude(false); This allows eager loading them via Include / ThenInclude. Include("Module. Id == id); But the samples in LinqPad explains this better. Jun 12, 2019 · As the entities of type Unite are linked to Entreprise AND themselves, i can tell EFCore to include only Entreprise. Oct 17, 2023 · Edit: I've successfully loaded the entirety of my model with this, it was slower than with split queries created by EF Core, but as the objective is only to load fragments, performance is not an issue (yet?) Edit 2: Comparison of manual includes with the above recursive method, made with BenchmarkDotNet (Runtime: . Say I have a Class Car, with Complex-typed Properties for Wheels, Doors, Engine, Bumper, Windows, Exhaust, etc. Items) . rcsx par tgk mzioi ovjfmj cacu nssjvwh wuurzv eivkhy ddpc arfts uisa eazfly hqnejid bhrbuy