private static void QueryDB()
{
ScoreDBContext db = new ScoreDBContext();
//IQuery VS IEnumable
//var query = from score in db.Scores
// group score by score.StuName into StuGroup
// select new
// {
// Name = StuGroup.Key,
// AvgScore = StuGroup.Aggregate(new ScoreStatic(), (acc, e) => acc.Accumlate(e), acc => acc.Computer())
// } into results
// orderby results.AvgScore
// select results;
var query = db.Scores.GroupBy(s => s.StuName)
.ToList()
.Select(g =>
{
return(new
{
Name = g.Key,
AvgScore = g.Aggregate(new ScoreStatic(), (acc, e) => acc.Accumlate(e), acc => acc.Computer())
});
})
.OrderByDescending(r => r.AvgScore);
query.ToList().ForEach(e =>
{
Console.WriteLine(e.Name + "\t" + e.AvgScore);
});
}
private static void CreateDB(List <Score> scores)
{
ScoreDBContext db = new ScoreDBContext();
if (db.Scores.Any())
{
return;
}
db.Scores.AddRange(scores);
db.SaveChanges();
}
