The following query works as long as I can add DataRelations. However, the relation "Table2Table3" may no longer be clearly defined, so I think I need to remove it. The old relation strictly joins on 2 string fields. The new relation exists if Table2.code = Table3.code and Table2.class = Table3.class OR Table2.code = Table3.code and Table2.class = "*" and Table3.class is anything. How can I implement this condition and still sum Table3.cost field? Can I use regular expressions? I tried creating an anonymous class equality (see far below), but Table2 was no accessible on the right side of the equals clause.
var querytest = from x in ds.Tables[0].AsEnumerable()
orderby x.Field<int>("Priority")
select new
{
Name = x.Field<string>("alias"),
Amount = x.GetChildRows("Table1Table2")
.Sum(product => product.GetChildRows("Table2Table3")
.Sum(tx => tx.Field<decimal>("cost")))
};
sample tables:
table1: list of aliases and priorities ----------------- ID alias priority 1 alias1 1 2 alias2 2 3 alias3 4 4 alias4 3
table2: children records joined to table1 by ParentID (1-to-many) ----------------- code class ParentID code1 class1 1 code2 class2 1 code3 class3 2 code4 class4 4 code5 * 3
table3: data, joined on new condition ----------------- code class cost code1 class1 1.00 code1 class1 10.00 code1 class1 26.00 code2 class2 5.00 code2 class2 0.00 code3 class3 1000.00 code5 class6 25.00 code5 class7 26.00
expected output:
alias1 42.00 alias2 1000.00 alias4 0.00 alias3 51.00
This query can't access "codes" in the scope of the second anonymous class:
var querytest2 = from aliases in ds.Tables[0].AsEnumerable()
join codes in ds.Tables[1].AsEnumerable()
on aliases.Field<int>("ID") equals codes.Field<int>("ParentID")
join data in ds.Tables[2].AsEnumerable()
on new {
code = codes.Field<string>("code"), classcode = codes.Field<string>("class") }
equals new {
code = data.Field<string>("code"), classcode = (data.Field<string>("class") == "*" ? codes.Field<string>("class") : data.Field<string>("class") }
orderby aliases.Field<int>("Priority")
select new
{
name = aliases.Field<string>("alias"),
cost = //somehow sum here
};