entity framework example

add such code in the User entityPublic virtual icollectionin the add such code in the User's constructorThis. Roles = new hashsetSimilarly, the role also contains multiple users, then the add such code to the Role entityPublic virtual icollectionin the add such code to the Role constructorThis. Users = new hashsetNext, we construct our inheritance from DataContext class of DbContext classpublic class datacontext:dbcontext{public DataContext () : Base ("DataContext") { } public

tables together to flatten them to provide a clearer perspective. When we query each poet's information through the Vwlibraties entity set, only one loop is needed. The output is slightly different because we repeat the poet's name in each poem. The last note in this example is that we did not insert poests,poems and meters through the view vwlibrary. Because in the vast majority of databases, views are re

Preface Before going into the details of the object framework, we will first discuss the convenience of data access from the traditional dataset Method to the object-based method, and how these two methods work differently to lead to the use of O/RM tools like Entity Framework. Use dataset and datareader as data containers Let's first look at an

code is very simple, but it is implemented using two nested loops.The last block of code uses the Vwlibrary entity, which is based on the Vwlibrary view. The Vwlibrary view joins tables together to flatten them to provide a clearer perspective. When we query each poet's information through the Vwlibraties entity set, only one loop is needed. The output is slightly different because we repeat the poet's nam

/article/details/41877301 introduction of quite detailed, I would like to remind you to remember your installation directory, will be used later.Question three:To get here, I thought I could build the model smoothly, and didn't expect this problem to occurFortunately, there are people on the internet who have the same problem, that is, the http://blog.csdn.net/niewq/article/details/41877301 of the great God aboveOverall, four steps:First, the Package Manager console, the Library installer packag

Entity Framework mappings to relational Relation Mapping (Entity Framework multi-to-Multi-link ing), entitymapping Generally, when we design a database, there will be two tables with many-to-many relationships. When the database has many-to-many relationships, we usually process them through intermediate join tables, s

Label:About VS2013 link MySQL EF6 Many of the online statements are broadly consistent, but the specific process may have some problems Comprehensive longitudinal said, refining a few points: 1. Install Mysql-for-visualstudio-1.2.3.msi (required) 2. Install Mysql-connector-net-6.9.4.msi (required) 3. Install the EF Install command (install-package entityframework) using the NuGet Packages Package Manager, note: Which project is installed and automatically adds App. config under the project after

example, we can use the count () method in the Where clause of a LINQ query to check whether the number of comments is greater than 0. In the entity SQL method, we can use count in the WHERE clause (select value 1 from p.comments ) >0. Both of these methods work fine, but the approach in Listing 3-10 is more concise, and from a performance standpoint, any () and exist () do not need to enumerate the entire

upper right corner. If it is not installed, click Download to install it. After the installation is complete, follow the steps below to optimize the code. 1. right-click the designer, select Add Code Generation Item, and select ADO. net poco Entity Generator, and enter Entities in the Name text box. tt: Click OK. The two files are added to the project: Entities. tt and Entities. context. tt. 2. Select the two files, right-click and select Run Custom

Http://www.cnblogs.com/sansi/archive/2012/10/18/2729337.htmlProgramming Entity Framework Second Edition translation indexYou can query the Entity Data model using various methods. You choose some methods because of your personal preferences, while others are because you can take advantage of special benefits. You've probably heard LINQ to Entities and

The original purpose of the translation and why choose the Entity Framework 6 Recipes to learn, please see the beginning of this series2-10 Table per Hierarchy inheritance modelingProblemYou have a database table that has a type or identification column. It can tell what the data in the row represents in your application. You want to model using table per hierarchy (TPH) inheritance mapping.Solution Solutio

This article is ADO. NET Entity Framework Series of articlesArticle 3: continue to demonstrate how to use the entity of ADO. NET Entity Framework as the data source of the data control to easily display data records in the Data Control. ADO. the first two articles of NET

Entity Framework Quick Start -- ModelFirst, entity -- modelfirst Entity Framework not only facilitates operation, but also considers user friendly interaction. The perfect combination of EF4.0 and vs2010 is also a reason for us to choose it. Compared with Nhibernate Microsof

storage models that represent relational architectures in databases. Relational databases usually store data in different ways than applications use data. Generally, this forces developers to retrieve data based on the structure of the database containing data. Therefore, developers usually load data into business entities that are more suitable for processing business rules. In this example, the relational database architecture is represented by a l

or view name, stored procedure name, or the parameters they require. You do not need to create the objects used to connect to the database, do not care about the structure of the returned data, and then use the code to convert them into objects. You only need to work with the conceptual model and code model entity classes. When you do this in the scope of EF, when EF is running, it processes database connections, database command generation, query

Entity Framework learning notes-EF introduction (an article tells you what EF is), entity learning notes Entity Framework is a data-oriented "Entity Framework" based on ADO. NET ". EF.

chapter, you will see what code translation you use to translate "Search for certain entities in addresses entityset ". The model command returns the address object type for your query. Note: As you will learn in this book, the Entity Data model allows you to inherit data types. Therefore, your model may have contact entities and customer entities. Customer is a type of contact. In this case, the contacts entityset serves as the package for the con

the object to the database and check it again. How does entity framework set a composite primary key? Multiple Primary keys are allowed, as shown below:Using System; using System. componentModel. dataAnnotations; using System. componentModel. dataAnnotations. schema; public class Entity {[Key, Column (Order = 0)] public int Key1 {get; set;} [Key, Column (Order =

Entity Mappings using Fluent API:Here, we'll learn how to configure an entity using the Fluent API.We'll use the following Student and standard domain classes of the school application. Public classstudent{ PublicStudent () {} Public intStudentID {Get;Set; } Public stringStudentname {Get;Set; } PublicDatetime? dateOfBirth {Get;Set; } Public byte[] Photo {Get;Set; } Public decimalHeight {Get;Set; } Publ

Description of Entity notes corresponding to the automatic association query and automatic association update navigation properties of Entity Framework, entityframework I. First, I want to know about the automatic association query of Entity Framework: Automatic association