entity framework 6 0

field: using (var ctx = new PortalContext()){ var citieNames = ctx.Cities .Where(c => c.ProvinceID == 3 c.ProvinceID > 10) .OrderBy(c => c.CityID) .Select(c => c.CityName); foreach (var cityName in citieNames) { Console.WriteLine(cityName); }} The LINQ Extension Method reads multiple fields: using (var ctx = new PortalContext()){ var cities = ctx.Cities .Where(c => c.ProvinceID == 3 c.ProvinceID > 1) .OrderBy(c => c.CityID) .Sele

RememberEntity Framework 4.1/4.3 (concept)I have introduced the definitions of objectcontext objectset and dbcontext and dbset. After using 4.0 for a long time, I made a transition to 4.3. During this transition, I knew and used dbcontext and dbset. It feels good. The following table shows the objectcontext objectset dbcontext dbset: DbcontextAPI feature (dbcontext API function) Relevant EF4Feature/class (related to functions/classes in EF

Entity Framework tutorial -- create an object data model, entityframework Create an object data model: This article will show you how to create an EDM SchoolDB database and understand the infrastructure module. The Entity Data Model (EDM) is a model used to describe the relationship between entities. The following uses Visual Studio 2012 and EF6 to create a Schoo

Original: ASP. MVC5 + EF6 Introductory Tutorial (5) Model and entity FrameworkArticle Source: slark.net-Blog Park http://www.cnblogs.com/slark/p/mvc-5-ef-6-get-started-model.htmlPrevious section: ASP. NET MVC 5 Getting Started Tutorial (4) View and ViewBagNext section: ASP. MVC5 + EF6 Tutorial (6) View Razor useSOURCE download: Click I downloadFirst, create model

Before writing: After six months of Java + Silverlight development, I felt very happy to go back to Asp.net development on the pure MS Platform. many other times have been spent on Silverlight, so this time I went back to Asp.net and made a book plan for myself. first of all, C #4.0 and my favorite Entity Framework 4.0 Fortunately, I got the Entity

User code not processed System.InvalidOperationExceptionhresult=-2146233079Message= The Entity Framework provider for the ADO-out provider with the fixed name "System.Data.SQLite" was not found. Make sure that the provider is registered in the "EntityFramework" section of the application configuration file. For more information, see http://go.microsoft.com/fwlink/?LinkId=260882.Source=entityframeworkStackTr

.Items.Clear (); varExpr = fromPinchEntity. T_userSelectp; foreach(varIteminchexpr) {LISTBOX1.ITEMS.ADD (string. Format ("{0}-{1}", item. Id, item. Name)); } } Private voidToolstripbutton1_click (Objectsender, EventArgs e) {ADD (); } Private voidToolstripbutton4_click (Objectsender, EventArgs e) {Edit (); } Private voidToolstripbutton3_click (Objectsender, EventArgs e) {Delete (); } Pr

Here I'm talking about the introduction to the Entity Framework. Download the Northwind database from the Web, create a new console program, and re-add an ADO Entity Data model."Gateway" (Operation context) for manipulating databases in EFDbContext encapsulates the connection between the. NET Framework and the database

Entity Framework 4 in action is my first English book I have read for so many years. At first I went to learn English in order to read this book. Later I simply read and read several chapters, the English reading capability has been greatly improved. Unfortunately, at the end, I did not learn anything substantive, but I learned English. Of course, I did not learn anything substantive, because most of my kno

Enable Entity Framework to support multiple databases Luo chaohui (http://kesalin.cnblogs.com /) This article follows the "signature-non-commercial use-consistency" creation public agreement EF supports SQL Server very well, both code first, model first, and database first, but it is not so friendly to non-Microsoft databases, currently, the only guarantee is that database first supports most datab

operations of LINQ to SQL consume almost 10 times of EF, the performance of ado.net in adding data is really unsatisfactory, which is also related to the underlying Writing of our project. From the test results, we can see that the average efficiency of EF is 6 times that of LINQ to SQL except that EF is delayed for 3 seconds (initially considered as the initialization time) during the first operation, it is four times more efficient than the curre

, generating one SQL at a time, as follows:This omission describes three of these sql,sql statements similar, just read the role attribute when the information is obtained according to different Roleid, so only the parameter values are differentFrom the above example can be seen in the loop several times in order to get the navigation properties generated a few SQL, if the database table has a large amount of data, such a way to the performance of the impact can be imagined. According to the abo

: }, 3. After changing the data model, run the following command in the project folder to add the new Migration Code: 1: dnx . ef migration add newBook 4. Run the Migration Code: 1: dnx . ef migration apply For more details, refer to "read the original article ". As far as my practical experience is concerned, there are several points to share with you: 1: public static void Init(IServiceProvider serviceProvider) 2: { 3: using (var db = serviceProvider.GetService 4:

LINQ to SQL queries can also improve performance. The ADO. Net team mentioned that in their internal tests, some modifications to the query parameter evaluation method have resulted in a 600% performance improvement. Although. net delivery and EF release are independent of each other. They still share some core libraries, including system. data. entity. DLL, system. data. entity. design. DLL and system.

Label: des style blog HTTP color Io ar JavaPreface LINQ (Language Integrated Query) is a group used for C # and VB.. Net Language extension, which allows the compilation of C # Or VB.. Net code, which operates the memory data in the same way as the query database. 7: LINQ to entities in the series of Entity Framework technology provides a wide range of SQL-like Query syntaxes, which are powerful and easy to

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 Microsoft, this is indeed a good job. The following is a simple example of codefirst. We are still following the previousArticleEntity Framework Quick Start --

Recently spent a lot of time in refactoring and further refining my web development framework, and strive to in the user experience and interface design, and WinForm development framework to maintain consistency, while on the web, I mainly use Easyui front-end Interface processing technology, take the MVC technology route, in the reconstruction process, Many details spend a lot of time on research and refin

: Instantiate DbContext to perform crud operations. 1 2 using (varnew schooldbentities ()) 3 { 4 5 // perform crud operations here: 6 } 7 View Code Get ObjectContext from DbContext: The APIs in DbContext in common tasks are easier to use than the ObjectContext API. Of course you can also get ObjectContext references from DbContext to use some of these methods. Can be done with Iobjectcontextadpter. 1 2 u

Full-width corners, which is differentiated in LINQ. Here's a real scene from the Cnblogstagservice project (a back-end service that provides a tag service for front-end applications based on the Entity Framework). Read a LINQ to Entities code First: Public list The code above is to query records from the database based on tagname, and then get the corresponding tag

(select * from sys.objects sowhere so.object_id=object_id(N'InsertBingMap')and so.type in (N'P'))drop procedure [dbo].[InsertBingMap]gocreate procedure [dbo].[InsertBingMap](@Name nvarchar(50), @GeoType nvarchar(50), @Locations nvarchar(max), @Latitude decimal(18,12), @Longitude decimal(18,12), @Radius decimal(18,12))asinsert into BingMap(Name,GeoType, Locations,Latitude,Longitude,Radius)values(@Name, @GeoType, geometry::STPolyFromText(@Locations,4326),@Latitude, @Longitude, @Radius)select * fr