public void CreateCoefs()
{
var courseTCs = new SpecialistDataContext().Courses.Where(x => x.IsActive)
.Select(x => x.ParentCourse_TC).Distinct().ToList();
var context = new RecRepository().GetContext();
context.DeleteMany <CourseCoef>(c => true);
var pairs = courseTCs.SelectMany(x => courseTCs.Select(y => Tuple.Create(x, y)))
.Where(x => string.Compare(x.Item1, x.Item2) > 0).ToList();
var i = 0;
var courseStudents = context.All <CourseStudent>().ToList()
.GroupByToDictionary(x => x.CourseTC, x => x.StudentId);
var cache = new List <CourseCoef>();
foreach (var p in pairs)
{
i++;
if (i % 100 == 0)
{
System.Console.WriteLine(i);
}
var x1 = courseStudents.GetValueOrDefault(p.Item1);
var x2 = courseStudents.GetValueOrDefault(p.Item2);
if (x1 == null || x2 == null)
{
continue;
}
var a = x1.Count;
var b = x2.Count;
var c = x1.Intersect(x2).Count();
if (c < 10)
{
continue;
}
var k = c * decimal.One * Math.Max(a, b) / ((a + b - c) * Math.Min(a, b));
var ck = new CourseCoef {
CourseTC = p.Item1, CourseTC2 = p.Item2, Coef = k * 100,
Count = c
};
cache.Add(ck);
}
context.AddMany(cache);
}
public void Delete()
{
var context = new RecRepository().GetContext();
context.DeleteMany <CourseStudent>(x => x.CourseTC.Contains("Архив"));
}