entity framework select

Entity Framework ArchitectureThe following figure shows the overall architecture of the Entity Framework. Let us now look at the architecture individually:EDM (Entity Data Model): EDM consists of three main parts-conceptual model, Mapping and Storage model.Conceptual Model:

No Entity Framework provider with the fixed name "System. Data. SqlClient" was found for issues encountered when using Entity Framework. Make sure that the provider is registered in the "entityFramework" section of the application configuration file. The provider is not found in ado. Problem description: The followin

Entity Framework Power Tools:Entity Framework Power Tools (currently in Beta 3) has been released. EF Power Tools is useful mainly in reverse engineering and generating read-only Entity Data Model for Code-first.Download and install Power Tools from VisualstudiogalleryAfter installing it, when your right click on the C

What is the entity FrameworkWriting and managing ADO is a tedious and boring task. Microsoft provides an ORM framework called "Entity Framework" for your app to automate the management of your database.Microsoft has given the following definition to the Entity Framework:EF i

the needs of the database, and data separation is difficult for applications to use. Designing an object model first is a top-down approach. The main advantage of top-down is that applications are almost independent from databases to shape their models. The disadvantage is that sometimes it may not be conducive to the organization of the database, and may also lose performance. Databases are an important part of applications. Therefore, model design and database design should be seamlessly c

that determines the name of the generated object, including the foreign key column in the Model check box When you click Finish, the wizard generates a model with three tables and a view. The wizard reads the FOREIGN KEY constraint from the database and deduces a one-to-many relationship between poet and poem (s), as well as a a-to-many relationship between meter and poem (s). Figure 2-9 Conceptual model Figure 2-9 shows a model that contains table poet,poem and meter, view vwlibrary. Now you

　　Using MySQL connection in vs2013 entityframework often encounters this problem: your project references the latest Entity Framework, but the version-compatible Entity Framework Data provider required for the data connection cannot be found. Exit this wizard, install a compatible provider, rebuild your project, and th

the name of the generated object, including the foreign key column in the Model check boxWhen you click Finish, the wizard generates a model with three tables and a view. The wizard reads the FOREIGN KEY constraint from the database and deduces a one-to-many relationship between poet and poem (s), as well as a a-to-many relationship between meter and poem (s).Figure 2-9 Conceptual modelFigure 2-9 shows a model that contains table poet,poem and meter, view vwlibrary.Now you have a model that you

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

When working with Entity Framework entities, most of the time we operate on entity model entities, a combination of database manipulation contexts that can be easily implemented using a variety of convenient means, such as LINQ, and everything looks good. However, if you consider using WCF, you may encounter a number of related traps or errors. Because the object

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 example. Su

/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