Nun, ich weiß nicht ohne Weiteres, ob es in die entsprechende SQL-Abfrage übersetzen werden, aber man konnte diese versuchen:
var query = from company in db.MyTable
let firstChar = company.CompanyName.Substring(0, 1).ToUpper()
group company by firstChar into grouped
select new { FirstChar = grouped.Key, Count = grouped.Count() };
Hier ist eine LINQ to Objects Beispiel:
using System;
using System.Collections.Generic;
using System.Linq;
class Test
{
static void Main()
{
var companies = new[] {
new { CompanyName = "One", CompanyID=1 },
new { CompanyName = "Two", CompanyID=2 },
new { CompanyName = "Three", CompanyID=3 },
new { CompanyName = "Four", CompanyID=4 },
new { CompanyName = "Five", CompanyID=5 },
new { CompanyName = "Six", CompanyID=6 },
};
var query = from company in companies
let firstChar = company.CompanyName.Substring(0, 1).ToUpper()
group company by firstChar into grouped
select new { FirstChar = grouped.Key, Count = grouped.Count() };
foreach (var entry in query)
{
Console.WriteLine(entry);
}
}
}
Ergebnis:
{ FirstChar = O, Count = 1 }
{ FirstChar = T, Count = 2 }
{ FirstChar = F, Count = 2 }
{ FirstChar = S, Count = 1 }
Bin ich zumindest zu Recht sagen, dass das, was man erwarten würde, zu sehen?
Es funktioniert für SQL. Nur so weiß es jeder. –