ado net entity framework step by step

... (WPF) Trang 21CHƯƠNG II: TÌM HIỂU ENTITY FRAMEWORK 5.0 II.1 Tổng quan về Entity Framework II.1.1 Giới thiệu về Entity Framework Microsoft® ADO.NET Entity Framework là một bộ ánh xạ đối tượng ... tiếp với ADO.NET data provider để gửi hoặc nhận dữ liệu EntityClient sử dụng Entity SQL để truy vấn ADO.NET Data Provider Là layer giao tiếp với cơ sở dữ liệu theo tiêu chuẩn ADO.Net EntityDataReader ... trên NET Framework có thể tích hợp với bất kì mã nào .NET Framework bao gồm bộ thực thi ngôn ngữ chung (Common Languge Runtime - CLR) và lớp thư viện NET Framework (FCL) CLR là nền tảng của NET Framework

Ngày tải lên: 27/11/2021, 09:06

... Trang 186 Microsoft ADO NET 4 Step by Step6 Test setting linked child fields to NULL when a parent record is deleted Set the ... ensure data integrity and data expectations between linked tables Trang 388 Microsoft ADO NET 4 Step by StepChapter 5 Quick Reference Add a table to a DataSet Define a DataSet instance. Define ... CInt(employees.Compute("Count(ID)", "Gender = 'F'")) Trang 792 Microsoft ADO NET 4 Step by StepComputing an Aggregate Value: C# 1 Open the “Chapter 6 CSharp” project from the installed

Ngày tải lên: 05/07/2014, 19:20

... Trang 1106 Microsoft ADO NET 4 Step by StepSummary This chapter introduced two ADO.NET features that enhance its core functionality: aggre-gates and ... is even easier because ADO.NET will guess at the correct structure of the data even if you don’t provide table design guidance Trang 3108 Microsoft ADO NET 4 Step by StepWriting XML To generate ... row-level tag instead <Customer ID="1"> Trang 9114 Microsoft ADO NET 4 Step by StepThis is accomplished by setting the DataColumn.ColumnMapping property for the relevant column

Ngày tải lên: 05/07/2014, 19:20

... data management between ADO.NET and external data sources Note ADO.NET includes an “Entity Client” provider that enables provider-like functionality to the new ADO.NET Entity Framework system It ... System. Data.SqlClient namespace. Note Prior to version 4 of ADO.NET, Microsoft also included a functional Oracle provider with the NET Framework This provider, stored in the System.Data.OracleClient ... an application, ADO.NET’s main purpose is to access and manipulate data in external data stores To enable this query-and-update functionality on the source data platform, ADO.NET includes a “command”

Ngày tải lên: 05/07/2014, 19:20

... single query You can generate them by sending a batch of two or more semicolon-delimited SELECT statements within a single SqlCommand object’s command text, or by executing a stored procedure that ... to remove the test record Summary This chapter introduced methods for issuing commands to an ADO.NET connected database, and using those commands to retrieve individual or tabular results The ... with a SqlDataReader, always call its Close or Dispose method. Trang 6Run a SQL query over an ADO.NET connection Create a SqlCommand instance. Set its CommandText property to the SQL statement

Ngày tải lên: 05/07/2014, 19:20

... needed, and adding it to the SqlCommand.Parameters collection When you execute the command, ADO.NET passes both the placeholder-laden SQL text and the parameter collection to the database for ... require specific preci-sion and scale values Use these properties to configure the data from ADO.NET’s point of view ■ ■ Size Similar to Precision and Scale, Size is commonly used for text and ... the direction of a parameter The SqlParameter class in-cludes a Direction property that tells ADO.NET which way data flows from your query’s data value to the stored procedure There are four available

Ngày tải lên: 05/07/2014, 19:20

... components working on a single database table, Customer. Trang 5170 Microsoft ADO NET 4 Step by StepDatabase ADO.NET Customer DataAdapter SELECT Fill Update INSERT UPDATE DELETE DataReader Original ... DataSet. Trang 9174 Microsoft ADO NET 4 Step by StepC# DataSet targetSet = new DataSet(); SqlDataAdapter workAdapter = new SqlDataAdapter( "SELECT * FROM Customer ORDER BY LastName", connectionString); ... Trang 1166 Microsoft ADO NET 4 Step by Step4 Just after the “Read the next set, which contains the orders” comment, add the follow-ing

Ngày tải lên: 05/07/2014, 19:20

... implementation, and be aware of changes to ADO.NET in future releases that might affect your use of such statements. Using Local Transactions ADO.NET includes support for transactions with a ... versiontrack = @OriginalRowVersion Note Some database platforms support statements that let you sidestep ADO.NET’s preference for optimistic concurrency The Oracle SELECT statement, for example, includes ... conflicts ADO.NET, with its focus on disconnected data processing, uses optimistic concurrency Unfortunately, this method leaves some applications open to data conflicts of the type expe-rienced by

Ngày tải lên: 05/07/2014, 19:20

... save or cancel the transaction’s overall changes. 204 Microsoft ADO.NET 4 Step by Step Using Distributed Transactions The .NET Framework includes support for distributed transactions through ... rolled back by the // database because it did not get a commit order. MessageBox.Show("Error undoing the changes: " + ex2.Message); } } 198 Microsoft ADO.NET 4 Step by Step Visual ... of these three lines raises an exception in the subsequent catch block. 200 Microsoft ADO.NET 4 Step by Step 7. Just after the “Do a rollback instead” comment, within the inner try block, add

Ngày tải lên: 05/07/2014, 19:20

... TransactionScope object’s Dispose method. Trang 6Microsoft ADO NET 4 Step by StepPart III Entity Framework Trang 8Chapter 13Introducing the Entity Framework After completing this chapter, you will be ... and parallel elements in the Entity Framework ADO.NET has been included with the NET Framework since its initial release in 2002 As the primary data layer of the Framework, it provides great ... the Entity Framework is, naturally, the Entity With its ADO.NET core, you might think, incorrectly, that an entity finds its parallel in the DataSet or DataTable Instead, the parallel for an entity

Ngày tải lên: 05/07/2014, 19:20

... 4<EntityContainer Name="StepSampleConnection" LazyLoadingEnabled="true"> <EntitySet Name="Customers" EntityType="StepByStep.Customer" /> <EntitySet ... Classes generated by the Framework implement in code the entities, properties, and associations defined in the model Understanding the Entity Framework’s Layers In the Entity Framework, you define ... model-made-real Trang 7Running Framework QueriesThe Entity Framework provides four key methods for querying data exposed by the entity model ■ ■ Write SQL-like queries using the Entity SQL language Chapter

Ngày tải lên: 05/07/2014, 19:20

... menu command, and choose either ADO.NET EntityObject Generator or ADO.NET Self-Tracking EntityObject Generator as the new item type You can also add these items by right-clicking the visual modeler ... code-generation items for use with Entity Framework models: ■ ■ ADO.NET EntityObject Generator This is the default type, and the same type Visual Studio uses internally by default to generate the object ... Visual Studio online help Summary This chapter continued the overview of the Entity Framework by introducing the ADO.NET Entity Data Model Designer and its associated database import wizard These

Ngày tải lên: 05/07/2014, 19:20

... SELECT, FROM, WHERE, GROUP BY, and ORDER BY clauses. SELECT list-of-fields FROM one-or-more-tables WHERE Boolean-expression GROUP BY aggregate-grouping-fields ORDER BY sort-by-fields As with standard ... T-SQL focuses on the logical tables and rows in the database Even when an Entity Framework model targets a SQL Server database, Entity SQL queries focus on the data as expressed through the conceptual model Writing Basic Queries Entity SQL selection ... updates are needed, the standard Entity Framework tools take over ■ ■ None of the batch query or stored procedure functionality found in T-SQL is available in Entity SQL Entity SQL does include support

Ngày tải lên: 05/07/2014, 19:20

... included with the Entity Framework, this is a small omission But if you need to push entity data into a standard ADO.NET structure, you will have to do so manually When using the EntityCommand.ExecuteReader ... an Entity Data Model The key classes for the EntityClient provider appear in the System.Data EntityClient namespace. Using the EntityClient provider to query data covers the same general steps ... and then ultimately through a provider such as the SQL Server ADO.NET provider The Entity Framework hosts its own data provider: the EntityClient provider This provider exposes much of the same

Ngày tải lên: 05/07/2014, 19:20

... two Framework base classes (introduced earlier in this chapter) that act as collections for named or anonymous entity types Trang 5280 Microsoft ADO NET 4 Step by StepConsider this simple Entity ... program prompts you to delete the customer, it successfully located the entity by ID. Trang 9284 Microsoft ADO NET 4 Step by StepUsing Query Builder Methods: Visual Basic Note This exercise continues ... returns only those instances that are found in both. Trang 7282 Microsoft ADO NET 4 Step by StepQuery Builder Method Entity SQL Equivalent Description Except EXCEPT Returns all records in the

Ngày tải lên: 05/07/2014, 19:20

... ordering imposed by earlier calls to OrderBy or OrderByDescending, LINQ provides the ThenBy and ThenByDescending extension methods This pair sorts results just like their OrderBy complements, ... together multiple OrderBy meth-ods, the results will be sorted only by the last (rightmost) OrderBy call. C# // - This sorts by tr.Name (ascending) ONLY! var results = transport.OrderByDescending( ... provider endows ordinary ADO.NET DataTable objects with the ability to participate fully in LINQ queries It does this by adding the necessary LINQ requirements to relevant ADO.NET classes This chapter

Ngày tải lên: 05/07/2014, 19:20

... Microsoft ADO.NET 4 Step by Step Calling Custom Database Functions: C# Note This exercise continues the previous exercise in this chapter. 1. Open the source code view for the StatesByYear form. ... NotSupportedException("Direct calls are not supported.") End Function 328 Microsoft ADO.NET 4 Step by Step This routine defines the function stub that both LINQ and Visual Studio’s IntelliSense ... related .NET Framework 4.0 release, Microsoft provided guidance on the future of its LINQ to SQL provider. This “Update on LINQ to SQL and LINQ to Entities Roadmap” blog entry posted by the ADO.NET

Ngày tải lên: 05/07/2014, 19:20

... to the visual experience Chapter 20 Quick Reference Include an entity class in a LINQ query Add the entity class to your project by writing its code, using the Object Relational Designer, or ... become part of the context that also hosts the entity classes LINQ to Entities includes a similar feature, but it requires you to create local NET stubs in your own code With LINQ to SQL, the ... = "StepSample"; sqlPortion.IntegratedSecurity = true; Adjust these statements as needed to provide access to your own test database 2 Open the source code view for the StatesByYear form

Ngày tải lên: 05/07/2014, 19:20

... to download Express products. 1 Create a new ASP.NET web application project. Trang 9374 Microsoft ADO NET 4 Step by Step2 Add a new ADO.NET Entity Data Model to the project (See the “Importing ... new ASP.NET web application project. 2 Add a new ADO.NET Entity Data Model to the project (See the “Importing Database Tables as Entities” exercise on page 227 in Chapter 14 for step by step instructions.) ... create a new service based on an Entity Framework model in just a few steps: 1 Create a new ASP.NET web application using either C# or Visual Basic. 2 Add an ADO.NET Entity Data Model to your project

Ngày tải lên: 05/07/2014, 19:20

... 63 in Where clause (LINQ) 296 .NET applications, types of configuration files 13 .NET developers, ADO.NET and 3 .NET Framework See also Entity Framework (EF) ADO.NET in 213 connection string builders ... from the EntitySetRights enumeration. C# config.SetEntitySetAccessRule("Customers", EntitySetRights.AllRead); Visual Basic config.SetEntitySetAccessRule("Customers", EntitySetRights.AllRead) ... Clients can add new entity records to an entity set. WriteReplace Clients can update entities When updating an individual entity, only those new property values supplied by the client are updated

Ngày tải lên: 05/07/2014, 19:21