linq to mysql

Dynamic LINQ query (dynamically construct Expression What is dynamic LINQ query? The compiling of LINQ is static, because C # is designed based on the principle of the static type system, and the type has been determined at the time of writing, that is, the query to be executed is known at the time of compilation, what are conditions and sorting methods. In most

Comparison of the Performance of a Group using the LinQ to SQL and non-LinQ methods. A data table with 476550 data records. Group A field and sort it by the field. This requirement is implemented by using the methods of LinQ to SQL and non-LinQ respectively, and then let's take a look at the performance comparison.

Linq Learning (III)-basic query and linq learning Query I. Main introduction Learn from the perspective of comparison between linq, SQL, and lambda. Usage of select, orderby, paging, group by, distinct, subquery, and in 1. select Query users and their self-introductions Linq to SQL From a in Blog_UserInfoselect n

As you know, LINQ can be used to query database objects (which I refer to as model objects in the Entity Framework), or to query IEnumerable objects in memory.There is nothing wrong with both queries, but when mixed together (usually with keywords to join connections), there is more to note.Scenario 1:linq to Object Connection (join) Linq to EntityLet's take a lo

This book is intended for personal learning and knowledge sharing. The copyright of this book is owned by the original author. If there is any infringement, please inform me that I will handle the post immediately.Reprinting is allowed, but this copyright statement is not allowed for commercial purposes!Blog: Han xilong Chapter 1LINQIntroduction Overview Through surfing the Internet, you can find instructions on language integration query (LINQ), suc

In this article, we'll go on to the previous article, "LINQ to SQL and Entity Framework (top)", and continue to use LINQ to SQL and the Entity Framework to practice "Interpreting queries" to learn the key features of these technologies. We are here to focus on the "LINQ" section in LINQ to SQL and the Entity Framework,

First, what is LINQLinq:language Integrated Query, the essence of which is to convert the ADO result set into an object set by reflection, along with the generic attribute, to realize the transformation of the or model.Second, advantages and disadvantagesPros: Encapsulate SQL statements, manipulate objects only, reduce code volumeDisadvantage: The pursuit of efficiency at the same time sacrificing performance, compared to the ADO performance is slightly worse, and the copy of the SQL statement i

Let's go on to the LINQ to SQL statement, which we'll talk about Union all/union/intersect operations and TOP/BOTTOM operations and paging operations and sqlmethods operations.Union All/union/intersect operationScenario: two sets of processing, such as append, merge, take the same items, intersect items and so on.Concat (Connection)Description: Connect a different collection. Do not actively filter the same; delay.1. Simple form:var q = (from C in

Tags: style blog color ar strong SP div on log1. One-to-manyvar expr = context. Products "LINQ to SQL" p.unitprice > 10m) New { p.productid, p.productname });var from inch context. Productswhere"LINQ to SQL" p.unitprice > 10m Selectnew { p.productid, p.productname };SELECT [Extent1].[ProductID] as

One, What is LINQ LINQ is the abbreviation for Language Integrated query (language integration queries). It is an important feature introduced by Microsoft in. NET 3.5. Since it was introduced by Microsoft, the corresponding programming is naturally the C # and Visual Basic languages. The role of 1,LINQ Let's use the same API (SQL-like syntax to query) to mani

C #3.0 LINQ ing of the LINQ database table [add this page to favorites] [print] Author: ITPUB Forum2008-01-17 Content Navigation: OverviewPage 1: Overview Linq to SQL is a database application of LINQ technology. Database technology from OLEDB, odbc to ado, to ado. net to the present of the

Document directory 1. Select 2. Where 3. OrderBy 4. Union Advanced features This article introduces the advanced features of LINQ, including the usage of dynamic queries that everyone cares about, and briefly introduces the knowledge of ID identification.Dynamic query An application may provide a user interface that allows you to specify one or more predicates to filter data. In this case, the details of the query are not known during compilatio

Label:DataContextDataContext, as the main entry point for the LINQ to SQL framework, provides us with methods and properties that illustrate several typical applications of DataContext in several examples.Creating and Deleting databasesThe CreateDatabase method is used to create a database on the server.The DeleteDatabase method is used to delete the database identified by the DataContext connection string. The name of the database is defined in the f

(Original: ash insects home http://hi.baidu.com/grayworm)LINQ to objects is the core of the LINQ family. Other LINQ also use the same query syntax as that of LINQ to objects.In the end, the compiler translates the LINQ syntax into a chained expression of the extension method

Continue this series from today. The good news is that Microsoft released the Simplified Chinese version of Visual Studio Team System February 1 Team Suite on April 9, 2008. You can download the 90-day trial version of Visual Studio Team System 2008 Team Suite Simplified Chinese version here. Today, I will briefly learn about open concurrency control and transaction content. For more information, see MSDN.Simultaneous Changes open Concurrency Control The following table describes the terms relat

In this series, we mainly introduce the basics of LINQ to SQL. Because of the powerful nature of LINQ, it has different contents for different data sources, this includes the SQL Server database's LINQ to SQL, the XML document's LINQ to XML, and the ADO. NET DataSet;.. NET collections, files, strings, and so on. In add

We will continue to explain the LINQ to SQL statements. In this article, we will discuss the Insert, Update, and Delete operations. This is the most common in our program. Let's look at the example.Insert/Update/Delete operation Insert (Insert) 1. Simple Form Note: A new object is added to the corresponding set using the InsertOnSubmit method and submitted to the database using SubmitChanges. NorthwindDataContext db = new NorthwindDataContext();var ne