c# - LINQ Summary of Nested Dictionary -

dictionary<datetime, dictionary<string, double>>

2015/6/1 10:30  table1  300,                 table2  600  2015/6/1 11:25  table1  200  2015/6/2 10:25  table1  200,                 table2  700 

how can these summary result

dictionary<datetime, dictionary<string, double>>

2015/6/1   table1  500,            table2  600  2015/6/2   table1  200,            table2  700 

you need flatten inner dictionary using selectmany after can apply groupby on datetime first (key in dictionary) , in result need again group tables. can project output dictionary. here complete code:-

dictionary<datetime,dictionary<string,double>> result =                        data.selectmany(x => x.value, (key, obj) => new { key, obj })                           .groupby(x => new { date = x.key.key.date })                           .select(x => new           {               date = x.key.date,               output = x.groupby(z => z.obj.key)                  .select(t => new { table = t.key, sum = t.sum(m => m.obj.value) })                  .todictionary(d => d.table, d => d.sum)           }).todictionary(x => x.date, x=> x.output); 

working fiddle.