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This article mainly introduces what the LINQ technology has, has a certain reference value, interested friends can refer to, I hope you can learn a lot after reading this article, the following let the editor take you to understand it.

.net Language-Integrated Query (LINQ, language integrated query) is a new technology provided by Microsoft. It can introduce the query function directly into the programming languages supported by .NET Framework 3.5 (such as C #, Visual Basic, etc.). Query operations can be communicated through the programming language itself, rather than embedded in the application code as a string.

LINQ technology mainly includes four independent technologies:

◆ LINQ to Objects

◆ LINQ to SQL

◆ LINQ to DataSet

◆ LINQ to XML

They query and process object data (such as collections, etc.), relational data (such as SQL Server databases, etc.), DataSet object data, and XML structure data (such as XML files), respectively. Using LINQ greatly reduces the code for querying or manipulating data in a database or data source, avoids SQL injection to some extent, and provides application security. If you want to master LINQ, you should follow the following learning order. First of all, you need to understand what LINQ is and how to build a development environment.

To know these basics, you need to master the basic syntax that supports LINQ in C # 3.0, such as implicit local variables, object initializers, anonymous types, implicit arrays, Lambda expressions, query expressions, extension methods, and expression trees. If you are not clear about these, it is recommended to find a book, such as Tsinghua Hongpi's "C# 3.0 self-study Book". Then you need to understand the three steps in the LINQ query operation: preparing the data source, creating the query, and executing the query. Then, you need to master the rules and usage of the LINQ query clause.

These clauses include select clause, from clause, where clause, orderby clause, group clause, into clause, join clause and let clause. Then master LINQ query operations, such as filtering operation, projection operation, collection operation, aggregation operation and so on. Once you have mastered these basic statements, you can learn how to apply them.

(1) the method of using LINQ to SQL to create object model and DBML file for SQL Server database, and the method of dealing with various types of results in DBML file.

(2) the properties and methods of the data context (DataContext) class, and the methods that use the properties and methods in the data context to query and process the data.

(3) the method of using LINQ to SQL to query and manipulate the data of SQL Server database.

(4) use LINQ to Objects to query and process the data in the collection object.

(5) use LINQ to DataSet to query and process data in DataSet objects.

(6) use LINQ to XML to query, create, modify and delete XML documents.

Once you have mastered the application, you can develop ASP.net or Windows.

Thank you for reading this article carefully. I hope the article "what are the LINQ technologies" shared by the editor will be helpful to you? at the same time, I also hope you will support us and pay attention to the industry information channel. More related knowledge is waiting for you to learn!

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