linq to mysql

How to handle the problem of the Linq Mysql GroupBy statement, linqgroupby The statement is as follows: var resumeList = db.ChannelResume.Where(model); var groupValues = resumeList.GroupBy(t => new {t.AgentId, t.AgentName}); var statistics = groupValues.Select(c => new ResumeStatisticsViewModel() { Date = dateSpan,

/bug.php?id=46742Http://stackoverflow.com/questions/15083627/linq-mysql-group-by-year-month-day-select-year-month-day-countBut no solution was seen.Then try to do a foreach loop directly on the groupvalues variable. varResumelist =db. Channelresume.where (model); varGroupvalues = resumelist.groupby (t =New{t.agentid, t.agentname}); foreach(varIteminchgroupvalues) {

LINQ: getting started with LINQ (1)-Introduction to LINQ query and linq QueryGetting started with LINQ (1)-Introduction to LINQ Query A query is an expression used to retrieve data from a data source. Over time, people have develo

LINQ: start to use LINQ (2)-Basic LINQ query operations, linq QueryGetting started with LINQ (2)-Basic LINQ query operations The first step is to specify the data source. Like in most programming languages, variables must be decla

LINQ: start to use LINQ (3)-use LINQ for data conversion, and use linq for Data ConversionGetting started with LINQ (3)-using LINQ for Data Conversion Language integration query (LINQ)

LINQ is a new thing, but from many articles and discussions, this concept is a bit chaotic. Therefore, we often see the following: Only data tables and object attributes can be matched one by one in LINQ ...... LINQ Development Guide: map database fields in LINQ ...... In fact, the above two statements refer to the

LINQ is a new thing, but from many articles and discussions, the concept is a bit confusing. So we can often see this: LINQ can only match data tables to entity attribute one by one ... LINQ Development Guide: Database field mapping in LINQ ... In fact, the above two sentences are all

= q.todictionary (p = p.productid);foreach(intKeyinchQdictionary.keys) {Console. WriteLine (key);}Statement Description: This sample uses todictionary to directly evaluate the query and key expression direct key expressions as dictionaryAdo. NET and LINQ to SQLLINQ to SQL is based on the services provided by the ADO provider model. As a result, we were able to mix LINQ to SQL code with existing ADO-out app

Introduction to Query expressions (LINQ) In the last two articles, I introduced the features and improvements of C #3.0 new language.ProgramIt provides us with great help. From the beginning of this article, we will start to discuss the LINQ. LINQ is short for Language Integrated Query, which is integrated in. net.Programming Language. It has become an integra

Linq learning summary 1-refer to the detailed description of Linq technology, 1-linqKey points:1. The set of linq operations must implement the IEnumerable interface. Therefore, before 3.0, the set that implements this interface must be converted to a Linq-enabled set through the Cast or TypeOf method; 2. the query exp

Linq learning summary 1-refer to the detailed description of Linq technology, 1-linq Two key points: 1. The set of linq operations must implement the IEnumerable interface. Therefore, before 3.0, the set that implements this interface must be converted to a Linq-enabled set

A more concise version will be published in the blog Hall (excluding the English version). I hope this article will help you! Allowed to reprint, trouble to indicate the source: http://www.cnblogs.com/hanxianlongOriginal article:Http://weblogs.asp.net/scottgu/archive/2007/05/29/linq-to-sql-part-2-defining-our-data-model-classes.aspx In Part 1 of my LINQ to SQL blog post series I discussed "What Is

LINQ to datasets require the use of System.Core.dll, System.Data.dll and System.Data.DataSetExtensions.dll, add references System.Data and System.Data.DataSetExtensions to the project.1. DataTable Read ListDataSet ds = new DataSet ();//Omit the DS's fill code datatable products = ds. tables["Product"];ienumerableDataSet ds = new DataSet ();//Omit the DS's fill code datatable products = ds. tables["Product"];var rows = products. AsEnumerable () . Se

db.Products where p.UnitsInStock Statement Description: In this example, the direct key expression of the query and key expression is directly calculated as a Dictionary ADO. NET and LINQ to SQL LINQ to SQL is based on the services provided by the ADO. NET provider program model. Therefore, we can mix the LINQ to SQL code with the existing ADO. NET applicati

Read the catalogue: The main design model of 1.LINQ frame 1.1. Chained design mode (System logic is designed in a pipelined way) 1.2. Chained Query method (stepwise processing of each work point in a query expression) Core design principle of 2.LINQ frame 2.1. Languages above the Managed language (LINQ query expressi

LINQ: starts to use LINQ (4)-LINQ to query the type relation of the operation.Start to use LINQ (4)-the type Relationship of the LINQ query operation. The data source, query itself, and query execution are strongly-typed. The types of variables in the query must be the same

1. Create two Relational Tables, student and class tables. Students and course schedules, as shown in the example. 2. Create a form in vs2010. And writeCodeAs follows: Namespace Linqtest{ Public Partial Class Frmmanytomany: Form{ Internal Static String Sqlconstr = @" Data Source = localhost; initial catalog = lxpower; user = sa; Pwd = " ; Public Frmmanytomany (){Initializecomponent ();} PrivateVoidFrmmanytomany_load (ObjectSender, eventargs E){Binddata ();} Private Void

Cause Recently, I 've seen comments about "LINQ is dead" and "playing with it", and even some cool people say"ProgramDevelopment will eventually return to the Local MachineCode", Do not say whether these comments are correct, and first let's take a look at your amazing comments. The following is only an excerpt: Remark 1 I think there are quite a few people in the garden who have learned and written a seriesArticle Ah ~~ What's the sorrow of prog

3]. Main design models of the LINQ framework At this point, we seem to be able to see the principle of LINQ. It is not an air garden, it has a foundation. With the support of a series of new features above, Microsoft builds a large-scale extension method to ensure that the above features can interact with each other and form a natural Integrated Query framework. The above features are all enhancements mad

1.1linq execution expression Before reading this article, I assume that you have some theoretical knowledge of my previous analysis, because the content of this chapter is based on a series of previous knowledge points, to ensure your reading is successful, we recommend that you read the first few articles in your own series of LINQ or you have a deep knowledge system on the principles of LINQ to prevent y