Linq关于EDM绑定DataGridView的查询帮助 [英] Linq query help on EDM bound DataGridView

问题描述

我有3张桌子:
公司(公司编号，公司名称)
高管(ExecutiveID，ExecutiveName)
CompanyExecutives(CompanyID，ExecutiveID，ExecutiveType，DateAppointed，DateResignation)

使用我的EDM，我正在设置Datagridview.Datasource =

Hi, I''ve 3 tables:
Company(CompanyID, CompanyName)
Executives(ExecutiveID, ExecutiveName)
CompanyExecutives(CompanyID, ExecutiveID, ExecutiveType, DateAppointed, DateResignation)

Using my EDM I am setting my Datagridview.Datasource =

public ObjectResult<CompanyExecutives> GetCompanyExecutivesList()
{
    // Check we have an ObjectContext
    if (entities == null) entities = new CompanySecretaryEntities();

    // Create a query from the entityset
    ObjectQuery<CompanyExecutives> companyexecutives = entities.CompanyExecutives;

    // Return the results
    return companyexecutives.Execute(MergeOption.AppendOnly);
}

但这只是用CompanyID，ExecutiveID和DateAppointed填充我的Datagridview.我想显示CompanyName代替CompanyID，ExecutiveName代替ExecutiveID.谁能建议我该怎么做?我正在尝试以下Linq查询；

But this is only populating my Datagridview with the CompanyID, ExecutiveID and DateAppointed. I''d like to display the CompanyName in place of CompanyID, ExecutiveName in place of ExecutiveID. Can anyone suggest how I should do this? I was trying the following Linq query;

//define the query
var query = from ce in entities.CompanyExecutives//.Include("Executives").Include("Companies")
    join exec in entities.Executives on ce.ExecutiveID equals exec.ExecutiveID
    join companies in entities.Companies on ce.CompanyID equals companies.CompanyID
        select new
        {
           companies.CompanyName,
           exec.ExecutiveName,
           ce.ExecutiveType,
           ce.DateAppointment,
           ce.DateResignation
        };

推荐答案

稍稍更改LInQ，您将得到结果:

Change your LInQ little bit and you will get the result:

var query = from ce in entities.CompanyExecutives//.Include("Executives").Include("Companies")
    join exec in entities.Executives on ce.ExecutiveID equals exec.ExecutiveID
    join companies in entities.Companies on ce.CompanyID equals companies.CompanyID
        select new
        {
           CompanyName = companies.CompanyName,
           ExecutiveName = exec.ExecutiveName,
           ExecutiveType = ce.ExecutiveType,
           DateAppointment = ce.DateAppointment,
           DateResignation = ce.DateResignation
        };

这篇关于Linq关于EDM绑定DataGridView的查询帮助的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！