小编Dav*_*ner的帖子

如何使用表达式树生成以下内容...

var people = context.Set<Person>();
var transactions = context.Set<FinancialTransaction>();

var dataview = people.Where( p => p.LastName == "Smith" );

var selection = dataview
        .Select( p => new
        {
            FirstName = p.FirstName,
            LastName = p.LastName,
            LastTransaction =
                transactions
                    .Where( t => t.AuthorizedPersonId == p.Id )
                    .Max( t => t.TransactionDateTime )
        } );

gReport.AutoGenerateColumns = true;
gReport.DataSource = selection.ToList();
gReport.DataBind();

我正在尝试使用Ethan Brown 在这里提供的LinqRuntimeTypeBuilder解决方案,但在如何为LastTransaction子查询创建表达式以及如何将查询绑定到GridView方面苦苦挣扎.

这就是我到目前为止......

var people = context.Set<Person>();
var transactions = context.Set<FinancialTransaction>();

var dataview = people.Where( p => p.LastName == "Smith" …