C# NET使用实体框架显示下拉列表中的数据
我需要在C# NET使用实体框架显示下拉列表中的数据,c#,asp.net,entity-framework,C#,Asp.net,Entity Framework,我需要在a.CompanyName中实现distinct,但它不起作用。我需要做什么 try { var listCompany = company.CompanyList(); companyList1.DataSource = listCompany.Select(a => new { a.CompanyName, a.CompanyId }).Distinct(); companyList1.DataTextField = "CompanyName";
a.CompanyName
中实现distinct,但它不起作用。我需要做什么
try
{
var listCompany = company.CompanyList();
companyList1.DataSource = listCompany.Select(a => new { a.CompanyName, a.CompanyId }).Distinct();
companyList1.DataTextField = "CompanyName";
companyList1.DataValueField = "CompanyId";
companyList1.DataBind();
}
catch (Exception)
{
throw;
}
你可以用
对序列的元素进行分组
上述查询将按公司名称对结果进行分组,然后选择第一条记录的CompanyName
和CompanyId
companyList1.DataSource = listCompany
.GroupBy(x => x.CompanyName)
.Select(a => new
{ CompanyName = a.First().CompanyName, CompanyId = a.First().CompanyId });