How can I sort the results of a LINQ query
I have the following query. Is there an easy way that I could sort the results in numeric order of RowKey. Currently RowKey is a string. I would like to sort _rowData and NOT modify this query as I want to try some different sort orders and I'm looking for one line changes and not to redo 开发者_开发问答the query.
var _rowData = (from qu in _que.GetAll(
u => u.PartitionKey == partitionKey )
select new {
qu.PartitionKey,
qu.RowKey,
qu.Style,
qu.ShortTitle,
ModifiedToString = String.Format("{0:MM/dd/yyyy HH:mm}", qu.Modified)
});
I want to do the sorting outside of the LINQ query. The reason is that actually I want to be able to let the user choose a sort of RowKey, ModifiedToString and ShortTitle.
When you use the OrderBy extension, you don't modify the original query, it just enumerates the same values:
var _rowData = ...
var _rowDataSortedByRowKey = _rowData.OrderBy( u => u.RowKey );
var _rowDataSortedByModifiedToString = _rowData.OrderBy( u => u.ModifiedToString );
var _rowDataSortedByShortTitle = _rowData.OrderBy( u => u.ShortTitle );
var _rowDataSortedByOther = _rowData.OrderBy( ... );
Try specifying the DataRowComparer.Default in the Distinct statement.
Example:
var query = (from c in functiongettable().AsEnumerable()
orderby c.Field<string>("Name")
select c).Distinc(DataRowComparer.Default);
You can use System.Linq.Enumerable.OrderByDescending()
Something like:
(from qu in _que.OrderByDescending(u => u.RowKey).GetAll(
u => u.PartitionKey == partitionKey )
You can order the elements of a LINQ query using the orderby keyword:
OrderBy - Simple 2
This sample uses orderby to sort a list of words by length.
public void Linq29() { string[] words = { "cherry", "apple", "blueberry" }; var sortedWords = from w in words orderby w.Length select w; Console.WriteLine("The sorted list of words (by length):"); foreach (var w in sortedWords) { Console.WriteLine(w); } }
The sorted list of words (by length):
apple cherry
You can also use the Enumerable.OrderBy Extension Method:
var sortedWords = words.OrderBy(w => w.Length);
If you want to order by different criteria, you can pass a different key selector for each criterion:
if (c == "Length")
sortedWords = words.OrderBy(w => w.Length);
else
sortedWords = words.OrderBy(w => w);
Here ya go:
_rowData.Sort((a, b) => Convert.ToInt32(a.Key).CompareTo(Convert.ToInt32(b.Key)));
Try using the OrderBy extension method in the System.Linq namespace:
http://msdn.microsoft.com/en-us/library/bb549264.aspx
This method will allow you to add ordering to your query conditionally.
var _rowData = (from qu in _que.GetAll(
u => u.PartitionKey == partitionKey )
select new {
qu.PartitionKey,
qu.RowKey,
qu.Style,
qu.ShortTitle,
ModifiedToString = String.Format("{0:MM/dd/yyyy HH:mm}", qu.Modified)
});
// Let's say the user has selected they want to sort by RowKey
// and ModifiedToString, but not ShortTitle.
bool sortByRowKey = true;
bool sortByModifiedToString = true;
bool sortByShortTitle = false;
var query = _rowData.AsQueryable();
if(sortByRowKey) {
query = query.OrderBy(x => x.RowKey);
}
if(sortByModifiedToString) {
query = query.OrderBy(x => x.ModifiedToString);
}
if(sortByShortTitle) {
query = query.OrderBy(x => x.ShortTitle);
}
// Now let's call ToList() to execute the query and get the ordered data.
var _orderedData = query.ToList();
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