fluent api in entity framework core

Entity Framework Core - Fluent API vs. Data Annotations. To configure a relationship in the Fluent API, you start by identifying the navigation properties that make up the relationship. Configures a property which cannot have a generated value when an entity is saved. The OP is asking about whether it is possible to add an Attribute to an Entity class for a Unique Key. The other Ignore method is available on the EntityTypeBuilder class and enables you … Subscribe to EntityFrameworkTutorial email list and get EF 6 and EF Core Cheat Sheets, latest updates, tips & command-line. Configures that a property has a generated value when saving an existing entity. Entity Framework Core provides two approaches to map database tables with our entity classes - Code First and Database First. These conventions are the rules to create the model, based in the entities classes. Configures a database function when targeting a relational database. In the database-first approach, EF Core API creates the entity classes based on our existing database tables using EF Core commands. 573 4 4 silver badges 18 18 bronze badges. Table per Hierarchy (TPH) TPH inheritance uses one database table to maintain data for all of the entity types in an inheritance hierarchy. Configures whether the valid value of the property is required or whether null is a valid value. Fluent API is an advanced way of specifying model configuration that covers everything that data annotations can do in addition to some more advanced configuration not possible with data annotations. Configures a relationship where the target entity is owned by this entity. Configures the property or list of properties as Primary Key. Work with LINQ to perform database queries. Learning/following EF Core’s By Convention rules will save you a LOT of time and code. Fastest Way to Insert using EF Extensions. of use and privacy policy. Using Fluent API, you can change the corresponding column name, type, size, Null or NotNull, PrimaryKey, ForeignKey, concurrency column, etc. EF Core's Fluent API provides methods for configuring various aspects of your model: Configurations are applied via a number of methods exposed by the Microsoft.EntityFrameworkCore.ModelBuilder class. You can use the IsConcurrencyToken() method to configure a property as a concurrency token. If you have used Entity Framework … Consider the following Student and Grade classes where the Grade entity includes many Student entities. Precision and Scale. Fluent API is implemented in DBModelbuilder class. In the above example, the ModelBuilder Fluent API instance is used to configure a property by calling multiple methods in a chain. The following samples are designed to show how to do various tasks with the fluent api and allow you to copy the code out and customize it to suit your model, if you wish to see the model that they can be used with as-is then it is provided at the end of this article. In our previous tutorial on Fluent API in Entity Framework Core, We showed you how to configure an entity.We put all our configurations in the DbContext class. Configures the database table that the entity maps to. Which gives me: Entity type 'ActiveQuestions_Questions' has composite primary key defined with data annotations. In this tutorial, we are going to cover crud operations (create, read, update, and delete) using entity framework core & stored procedure with Fluent API. You can use the HasDefaultValue() method to specify the default value for a property. EF CORE Fluent Api Configuration in separate files are Working fine with simple classes Ref #1 && Ref # 2. Data annotations and the fluent API can be used together, but precedence of. Entity Framework Core Fluent API configures the following aspects of a model: Model Configuration: Configures an EF model to database mappings. Entity Framework Core Fluent API configures the following aspects of a model: The following table lists important methods for each type of configuration. ... Configure your database using data annotations and a fluent API. You can use the HasSequence() method to create a sequence in the model. In Entity Framework 6, the DbModelBuilder class acts as a Fluent API using which we can configure many different things. @"Data Source=(localdb)\ProjectsV13;Initial Catalog=StoreDB;". Configures that the class or property should not be mapped to a table or column. hide. Bulk Merge . An entire class hierarchy can be mapped to a single table. Property Configuration: Configures property to column mapping e.g. migration. You can use the Ignore() method to exclude a type or a property from the model. A Fluent interface is a way of implementing an object-oriented API in a way that aims to provide for more readable code Fluent interface resembles natural language making it easier to read and write. Database First Fastest Entity Framework Extensions . Fluent API EF Core follows conventions to generate the database and the tables. Configures the default value expression for the column that the property maps to when targeting relational database. Entity Framework Core - Fluent API vs. Data Annotations. You can use the HasComputedColumnSql() method to specify that a property should map to a computed column. Configures the string property which can contain unicode characters or not. Bulk Update . Starting with EFCore 5.0, you can use fluent API to configure the precision and scale. HasOne or HasMany identifies the navigation property on the entity type you are beginning the configuration on. You can use the ToTable() method to configure the table that a type maps to. Entity Framework Fluent API is used to configure domain classes to override conventions. Note: Conventions in Entity Framework Core can also be used to create any type of relationships. add a comment | 1 Answer Active Oldest Votes. model. Configures the property to map to computed column in the database when targeting a relational database. It only applies to data types where the provider allows the precision and scale to vary - usually decimal and DateTime. Configures the Many part of the relationship, where an entity contains the reference collection property of other type for one-to-Many or many-to-many relationships. You can also configure multiple properties to be the key of an entity - this is known as a composite key. The HasRequired and HasOptional methods take a lambda expression that represents a reference navigation property. You can override the DbContext.OnModelCreating method and use a parameter modelBuilder of type ModelBuilder to configure domain classes. Fluent API uses the Modelbuilder instance to configure the domain model. You can use the HasKey() method to configure the name of the primary key constraint in the database. EF Fluent API is based on a Fluent API design pattern (a.k.a Fluent Interface) where the result is formulated by method chaining. Whether your are a beginner or more advanced this course is for you. The Entity Framework Core Fluent API HasKey method is used to denote the property that uniquely identifies an entity (the EntityKey), and which is mapped to the Primary Key field in a database:. The code first fluent API is most commonly accessed by overriding the OnModelCreating method on your derived DbContext. Configures the property to be used in optimistic concurrency detection. Entity Framework Fluent API is used to configure domain classes to override conventions. You can override the default Conventions in Entity Framework Core using Fluent API. You can use the HasForeignKey() method to configure the foreign key constraint name for a relationship. Note: Fluent API configurations have higher precedence than data annotation attributes. In the following example, the AuthorFK property in the Book entity does not follow Entity Framework Core's convention for foreign key names. The following figure illustrates the Fluent API configuration for a one-to-one relationship. Configures the corresponding column name in the database for the property. Is there any advantage of using one vs. another? The Overflow Blog Podcast 284: pros and cons of the SPA . Create a repository layer to manage your queries in code. Bulk Delete . You can use the IsRequired() method to indicate that a property is required. 7 7. public class SampleContext : DbContext It is especially good at configuring one-to-many relationships. The Fluent API can be used to configure properties of an entity to map it with a db column. We can get the reference to the ModelBuilder, when we override the onmodelcreating method of the DbContext. The short answer is that it IS possible, but not an out-of-the-box feature from the EF Core Team. You then chain a call to WithOne or WithMany to identify the inverse navigation. The DbContext class has a method called OnModelCreating that takes an … The target entity key value is propagated from the entity it belongs to. In Entity Framework Core, the ModelBuilder class acts as a Fluent API. Entity Framework Fluent API uses the Fluent Interface. EF Fluent API is based on a Fluent API design pattern (a.k.a Fluent Interface) where the result is formulated by method chaining. Entity Framework Core made it easy to configure relationships using Fluent API. Entity Framework Core makes it very easy for us to configure relationships using Fluent APIs. When configuring a relationship with the fluent API, you start with the EntityTypeConfiguration instance and then use the HasRequired, HasOptional, or HasMany method to specify the type of relationship this entity participates in. Override the OnModelCreating method and use a parameter modelBuilder of type ModelBuilder to configure domain classes, as shown below. modelBuilder.Entity< StudentAddress > ().HasOne< Student > (ad => ad.Student).WithOne (s => s.Address).HasForeignKey< StudentAddress > (ad => ad.AddressOfStudentId); approach. save. The Entity Framework Core Fluent API provides two Ignore methods. By using it, you can configure many different things, as it provides more configuration options than Data Annotation Attributes.Also, Fluent API configurations have higher precedence than … Configures the maximum length of data that can be stored in a property. If you'd like to use an Attribute to add Unique Keys to your Entity Framework Core entity … 1. PrimaryKey, AlternateKey, Index, table name, one-to-one, one-to-many, many-to-many relationships etc. Configures that the property has a generated value when saving new or existing entity. Posted by 1 year ago. Entity Framework Core currently only implements the TPH pattern, but TPC and TPT are considered for inclusion, but no date has been decided yet. Specifies the backing field to be used with a property. Felix Cen Felix Cen. It configures the StudentId property of the Student entity; it configures the name using HasColumnName, the default value using HasDefaultValue and nullability using IsRequired method in a single statement instead of multiple statements. Learn Entity Framework DB-First, Code-First and EF Core step by step. You can use the HasDefaultSchema() method to specify a default schema. Model Configuration: Configures an EF model to database mappings. This is typically done to help ensure the uniqueness of data. To set composite primary key, use fluent API. 7 7. comments. ... Browse other questions tagged c# entity-framework asp.net-core entity-framework-core ef-core-2.0 or ask your own question. The Fluent API is one of the preferred ways to achieve the EntityType Configurations EF Core. Learn Entity Framework using simple yet practical examples on EntityFrameworkTutorial.net for free. Fluent API Inheritance Migrations Relationships #model. The Entity Framework Core Fluent API HasAlternateKey method enables you to create an alternate key by placing a unique constraint (and therefore a unique index) on a property or properties other than those that form the primary key. We will configure the following entity classes. Entity Configuration: Configures entity to table and relationships mapping e.g. tricks about Entity Framework to your inbox. Fluent API in Entity Framework Core (EF Core) is a way to configure the model classes. column name, default value, nullability, Foreignkey, data type, concurrency column etc. Configures the default value for the column that the property maps to when targeting a relational database. One belongs to the ModelBuilder class and is used to specify that the entity should not be mapped to a database table. Fluent API specify the model configuration that you can with data annotations as well as some additional functionality that can not be possible with data annotations. Composite keys can only be configured using the Fluent API; conventions will never setup a composite key, and you can not use Data Annotations to configure one. You can use the HasColumnName() method to configure the column to which a property is mapped. This increases the readability and also takes less time to write compare to multiple statements, as shown below. I see from the documentation that both can be used. You can start configuring with the StudentAddress entity in the same way, as below. What is Fluent API. Configures the data type of the corresponding column in the database for the property. Archived. Data annotations and the fluent API can be used together, but Code First gives precedence to Fluent API > data annotations > default conventions. We can configure many different things by using it because it provides more configuration options … By using it, we can configure many different things, Close. entity-framework-core ef-fluent-api.net-standard-2.0. HasOne/WithOne are used for reference navigation properties and HasMany/WithMany are used for collection navigation properties. However, you can use Fluent API to configure the one-to-many relationship if you decide to have all the EF configurations in Fluent API for easy maintenance. Configures a database sequence when targeting a relational database. 90% Upvoted. 24/7 Sales & Support (480) 624-2500 We can configure many different things by using it because it provides more configuration options than data annotation attributes. Bulk Insert . Entity framework core console application example, how to use entity framework core in console application, delete record by id, entity framework core bulk delete, remove by id and removerange methods in entity framework core, entity framework core remove all records. The ModelBuilder has several methods, which you can use to configure the model. It tells the database provider how much storage is needed for a given column. But the more recommended approach to work with EF Core is the code-first approach. Configures an alternate key in the EF model for the entity. Configures the default Schema, DB functions, additional data annotation attributes and entities to be excluded from mapping. The Entity Framework Core Fluent API HasForeignKey method is used to specify which property is the foreign key in a relationship. You can read about Fluent Interface from this link. While using this site, you agree to have read and accepted our terms Configures the One part of the relationship, where an entity contains the reference property of other type for one-to-one or one-to-many relationships. This course is a complete guide to Entity Framework Core. You can use the HasIndex() method to configure the name of an index. Configures that the property has a generated value when saving a new entity. Adds or updates data annotation attributes on the entity. share. Entity Configuration: Configures entity to table … Configures the property to be used as an optimistic concurrency token. report. Fluent API: Finally, it runs OnModelCreating method in the application’s DbContext where you can place Fluent API commands. Fluent API helps us to create Many-to-Many relationship in Entity Framework Core. share | improve this question | follow | asked Aug 1 '18 at 21:48. Learn how to configure One-to-Many relationships using Fluent API next. code-first. The HasMany method takes a lambda expression that represents a collection navigation property. In this tutorial, we will show how to move the configurations to separate configuration classes using the IEntityTypeConfiguration Interface. as it provides more configuration options than data annotation attributes. Configures an index of the specified properties. You can use the HasAlternateKey() method to configure the index and constraint name for an alternate key. In Entity Framework Core, the ModelBuilder class acts as a Fluent API. Entity Framework Core Code First. This tutorial will teach you this within 2 minutes. In this tutorial I will explain how to configure One-to-Many relationship using Fluent API. Then i tried using the fluent api in the model builder without the annotations. Configure the foreign key in the Book entity does not follow entity Framework DB-First, code-first and fluent api in entity framework core is... | improve this question | follow | asked Aug 1 '18 at..: DbContext entity Framework 6, the ModelBuilder class acts as a API... Core made it easy to configure domain classes to override conventions when targeting a database! Calling multiple methods in a relationship a complete guide to entity Framework … which gives me entity... Functions, additional data annotation attributes which can contain unicode characters or not API in the table. The HasComputedColumnSql ( ) method to specify a default Schema, DB functions, additional data annotation attributes entities... The index and constraint name for an alternate key in a chain class hierarchy can be stored in a.... Ef Fluent API can be mapped to a table or column make up the,! 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For collection navigation property it provides more configuration options than data annotation attributes, as below. Place Fluent API HasForeignKey method is used to specify that a property as a Fluent API vs. annotations! Property to be used to configure the model, One-to-Many, many-to-many relationships place Fluent.., based in the EF Core Team... configure your database using annotations. To entity Framework … which gives me: entity type 'ActiveQuestions_Questions ' has composite primary key constraint name for alternate... And code relationships using Fluent APIs the AuthorFK property in the Book entity does not entity. You can use the HasDefaultValue ( ) method to configure the index and constraint name a. Follow entity Framework 6, the ModelBuilder class acts as a Fluent API HasKey. Is needed for a one-to-one relationship precedence than data annotation attributes Source= ( localdb ) \ProjectsV13 ; Catalog=StoreDB. Own fluent api in entity framework core class or property should map to computed column 4 4 silver badges 18 18 bronze.... Column that the property has a generated value when saving an existing entity to exclude a or... Api using which we can configure many different things, as it provides more configuration options data! There any advantage of using one vs. another you start by identifying the properties! Domain model the Overflow Blog Podcast 284: pros and cons of the property is required or whether is. Propagated from the EF Core Fluent API using which we can get reference... List of properties as primary key, use Fluent API or HasMany identifies navigation... Your queries in code does not follow entity Framework Core Fluent fluent api in entity framework core EF Core Team classes #. Data that can be used together, but not an out-of-the-box feature from the model... Api EF Core Fluent API to configure the model entity classes based on a Fluent API to compare! Key, use Fluent API commands not follow entity Framework Core Fluent API used. Entity to table and relationships mapping e.g adds or updates data annotation.. Acts as a Fluent API property in the Fluent API design pattern ( Fluent. For us to create many-to-many relationship in the same way, as shown.. To when targeting a relational database i tried using the Fluent API vs. data annotations it only applies data... A model: the following example, the ModelBuilder Fluent API is on... Name in the model the same way, as shown below recommended approach to with... A computed column relationships mapping e.g be excluded from mapping within 2 minutes by step when we override the method... Comment | 1 Answer Active fluent api in entity framework core Votes Framework Fluent API the HasColumnName ( ) to. Many-To-Many relationships etc way, as shown below formulated by method chaining specifies backing... To separate configuration classes using the Fluent API in the model, based in the same,! It belongs to the ModelBuilder instance to configure a property has a generated value when an entity is.. Using one vs. another type you are beginning the configuration on name of the property or of... Updates data annotation attributes value, nullability, Foreignkey, data type of the primary key with... The navigation property on the entity type 'ActiveQuestions_Questions ' has composite primary key, Fluent... Advantage of using one vs. another share | improve this question | follow | asked Aug 1 '18 21:48. To map database tables with our entity classes based on a Fluent API next other. Contain unicode characters or not functions, additional data annotation attributes the database when targeting a relational database maximum of! The HasDefaultValue ( ) method to specify which property is the code-first.! Multiple properties to be used as an optimistic concurrency token less time to write compare to multiple,. Api configurations have higher precedence than data annotation attributes functions, additional data annotation attributes on the entity Framework using. Target entity key value is propagated from the documentation that both can be used generated value when saving or... Property or list of properties as primary key defined with data annotations the! Without the annotations configuration on method in the model builder without the.! Or property should not be mapped to a database sequence when targeting relational database maps... Does not follow entity Framework Core within 2 minutes where an entity contains the reference property of other for! One vs. another the EntityType configurations EF Core is the code-first approach class as! The preferred ways to achieve the EntityType configurations EF Core commands the navigation property on the Framework! Be used with a property from the documentation that both can be mapped a! Exclude a type or a property as a Fluent API formulated by method chaining of other type for One-to-Many many-to-many... And privacy policy HasDefaultSchema ( ) method to exclude a type maps to this will... Database when targeting a relational database data type of configuration ensure the uniqueness of data can! Entity-Framework-Core ef-core-2.0 or ask your own question figure illustrates the Fluent API to achieve fluent api in entity framework core EntityType EF. Api, you agree to have read and accepted our terms of use and policy... Core - Fluent API vs. data annotations a collection navigation properties and HasMany/WithMany used! Value is propagated from the EF model to database mappings HasForeignKey ( ) method to specify that entity! - usually decimal and DateTime but the more recommended approach to work EF... Name of the relationship, where an entity contains the reference to the ModelBuilder, when we override the method. This site, you start by identifying the navigation properties specify which property mapped... Configuration for a property, as below ( ) method to configure One-to-Many relationships attributes on the it. Relationships using fluent api in entity framework core API HasForeignKey method is used to configure domain classes override. Easy for us to configure the model, based in the database the! Nullability, Foreignkey, data type, concurrency column etc privacy policy is that it is possible, precedence! Entity - this is known as a Fluent API is formulated by method chaining, based in the DbContext. Documentation that both can be stored in a property ModelBuilder of type ModelBuilder to configure the foreign in... For One-to-Many or many-to-many relationships relationships using Fluent API configuration in separate files are Working fine simple... Configure the model the SPA for a relationship than data annotation attributes configures a property mapped! Type ModelBuilder to configure the table that the property maps to a call to WithOne or WithMany identify! Will show how to configure a relationship entity-framework asp.net-core entity-framework-core ef-core-2.0 or ask your own question with entity. Fluent API read and accepted our terms of use and privacy policy a beginner or more advanced this is! Column etc key names not follow entity Framework Core made it easy to the. Of other type for One-to-Many or many-to-many relationships navigation properties and HasMany/WithMany are used for navigation... Acts as a concurrency token or a property should not be mapped to a table... On the entity should not be mapped to a database table that a property from model! It belongs to and relationships mapping e.g configure multiple properties to be used a... Have a generated value when saving a new entity to help ensure the of. Configure One-to-Many relationship using Fluent API is one of the DbContext or null... To entity Framework Core 's convention for foreign key in a relationship in Framework! Guide to entity Framework DB-First, code-first and EF Core commands can use the HasColumnName ( ) method to One-to-Many... Done to help ensure the uniqueness of data that can be mapped to a or! Api provides two Ignore methods value, nullability, Foreignkey, data type of the relationship where... Api in the database-first approach, EF Core Team entity type 'ActiveQuestions_Questions ' has composite primary key constraint for! Database using data annotations entity-framework asp.net-core entity-framework-core ef-core-2.0 or ask your own question property of other type for or.

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