I m working with a set of legacy DAO code that returns an IList, where each Hashtable represents the row of a dynamically executed SQL query. For example, the List might contain the following records/hashtables:
Hashtable1:
Key:Column15, Value:"Jack"
Key:Column16, Value:"Stevens"
Key:Column18, Value:"7/23/1973"
Key:Column25, Value:"Active"
Hashtable2:
Key:Column15, Value:"Melanie"
Key:Column16, Value:"Teal"
Key:Column18, Value:"null"
Key:Column25, Value:"Inactive"
Hashtable3:
Key:Column15, Value:"Henry"
Key:Column16, Value:"Black"
Key:Column18, Value:"3/16/1913"
Key:Column25, Value:"Active"
Use of a static type instead of a Hashtable is out of the question because the result of the query is unknown at run time; both the number of columns and the nature of those columns is completely dynamic.
I d like to be able to perform Linq based operations on this data set (grouping, ordering etc), but I absolutely can t get my head around what the syntax might look like. As a simple example, let s say I want to sort the list by Column15 descending. The best syntax I ve come up with is:
var rawGridData = (List<Hashtable>) _listDao.GetListGridContents(listID, null, null);
var sortedGridData = rawGridData.OrderBy(s => s.Keys.Cast<string>().Where(k => k == "Column15"));
However, this yields an exception when sortedGridData is enumerated: "At least one object must implement IComparable."
I ve been struggling with this problem for days and am near my wit s end...please help!